Ilya Zakharevich > UI-KeyboardLayout-0.63 > UI::KeyboardLayout



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Module Version: 0.63   Source   Latest Release: UI-KeyboardLayout-0.67


UI::KeyboardLayout - Module for designing keyboard layouts


  #!/usr/bin/perl -wC31
  use UI::KeyboardLayout; 
  use strict;

  # Download from

  UI::KeyboardLayout::->set__value('ComposeFiles',      # CygWin too
  my $i = do {local $/; open $in, '<', 'MultiUni.kbdd' or die; <$in>}; 
  # Init from in-memory copy of the configfile
  my $k = UI::KeyboardLayout:: -> new_from_configfile($i)
             -> fill_win_template( 1, [qw(faces CyrillicPhonetic)] ); 
  print $k;
  open my $f, '<', "$ENV{HOME}/Downloads/NamesList.txt" or die;
  my $k = UI::KeyboardLayout::->new();
  my ($d,$c,$names,$blocks,$extraComb,$uniVersion) = $k->parse_NameList($f);
  close $f or die;
  $k->print_compositions  ($c);
  my $l = UI::KeyboardLayout::->new(); 

  my $l = UI::KeyboardLayout::->new_from_configfile('examples/EurKey++.kbdd');
  for my $F (qw(US CyrillicPhonetic)) {         
        # Open file, select() 
    print $l->fill_win_template(1,[qw(faces US)]);



Ilya Zakharevich,


In this section, a "keyboard" has a certain "character repertoir" (which characters may be entered using this keyboard), and a mapping associating a character in the repertoir to a keypress or to several (sequential or simultaneous) keypresses. A small enough keyboard may have a pretty arbitrary mapping and remain useful (witness QUERTY vs Dvorak vs Colemac). However, if a keyboard has a sufficiently large repertoir, there must be a strong logic ("orthogonality") in this association - otherwise the most part of the repertoir will not be useful (except for people who have an extraordinary memory - and are ready to invest part of it into the keyboard).

"Character repertoir" needs of different people vary enormously; observing the people around me, I get a very narrow point of view. But it is the best I can do; what I observe is that many of them would use 1000-2000 characters if they had a simple way to enter them; and the needs of different people do not match a lot. So to be helpful to different people, a keyboard should have at least 2000-3000 different characters in the repertoir. (Some ballpark comparisons: MES-3B has about 2800 characters; Adobe Glyph list corresponds to about 3600 Unicode characters.)

To access these characters, how much structure one needs to carry in memory? One can make a (trivial) estimate from below: on Windows, the standard US keyboard allows entering 100 - or 104 - characters (94 ASCII keys, SPACE, ENTER, TAB - moreover, C-ENTER, BACKSPACE and C-BACKSPACE also produce characters; so do C-[, C-] and C-\ C-Break in most layouts!). If one needs about 30 times more, one could do with 5 different ways to "mogrify" a character; if these mogrifications are "orthogonal", then there are 2^5 = 32 ways of combining them, and one could access 32*104 = 3328 characters.

Of course, the characters in a "reasonable repertoir" form a very amorphous mass; there is no way to introduce a structure like that which is "natural" (so there is a hope for "ordinary people" to keep it in memory). So the complexity of these mogrification is not in their number, but in their "nature". One may try to decrease this complexity by having very easy to understand mogrifications - but then there is no hope in having 5 of them - or 10, or 15, or 20.

However, we know that many people are able to memorise the layout of 70 symbols on a keyboard. So would they be able to handle, for example, 30 different "natural" mogrifications? And how large a repertoir of characters one would be able to access using these mogrifications?

This module does not answer these questions directly, but it provides tools for investigating them, and tools to construct the actually working keyboard layouts based on these ideas. It consists of the following principal components:

Unicode table examiner

distills relations between different Unicode characters from the Unicode tables, and combines the results with user-specified "manual mogrification" rules. From these automatic/manual mogrifications, it constructs orthogonal scaffolding supporting Unicode characters (we call it composition/decomposition, but it is a major generalization of the corresponding Unicode consortium's terms).

Layout constructor

allows building keyboard layouts based on the above mogrification rules, and on other visual and/or logical directives. It combines the bulk-handling ability of automatic rule-based approach with a flexibility provided by a system of manual overrides. (The rules are read from a .kbdd Keyboard Description file.

System-specific software layouts

may be created basing on the "theoretical layout" made by the layout constructor (currently only on Windows, and only via KBDUTOOL route).

Report/Debugging framework

creates human-readable descriptions of the layout, and/or debugging reports on how the layout creation logic proceeded.

The last (and, probably, the most important) component of the distribution is an example keyboard layout created using this toolset.

Keyboard description files ^


I could not find an appropriate existing configuration file format, so was farced to invent yet-another-config-file-format. Sorry...

Config file is for initialization of a tree implementing a hash of hashes of hashes etc whole leaves are either strings or arrays of strings, and keys are words. The file consists of "sections"; each section fills a certain hash in the tree.

Sections are separated by "section names" which are sequences of word character and / (possibly empty) enclosed in square brackets. [] is a root hash, then [word] is a hash reference by key word in the root hash, then [word/another] is a hash referenced by element of the hash referenced by [word] etc. Additionally, a section separator may look like [visual -> wordsAndSlashes].

Sections are of two type: normal and visual. A normal section consists of comments (starting with #) and assignments. An assignment is in one of 4 forms:


The first assigns a string value to the key word in the hash of the current section. The second adds a value to an array referenced by the key word; the other two add several values. Trailing whitespace is stripped.

Any string value without end-of-line characters and trailing whitespace can be added this way (and values without commas or without slash can be added in bulk to arrays). In particular, there may be no whitespace before = sign, and the whitespace after = is a part of the value.

Visual sections consist of comments, assignments, and content, which is the rest of the section. Comments after the last assignment become parts of the content. The content is preserved as a whole, and assigned to the key unparsed_data; trailing whitespace is stripped. (This is the way to insert a value containing end-of-line-characters.)

In the context of this distribution, the intent of visual sections is to be parsed by a postprocessor. So the only purpose of explicit assignments in a visual section is to configure how the rest is parsed; after the parsing is done (and the result is copied elsewhere in the tree) these values should better be not used.

Semantic of visual sections

Two types of visual sections are supported: DEADKEYS and KBD. A content of DEADKEYS section is just an embedded (part of) .klc file. We can read deadkey mappings and deadkey names from such sections. The name of the section becomes the name of the mapping functions which may be used inside the Diacritic_* rule (or in a recipe for a computed layer).

A content of KBD section consists of #-comment lines and "the mapping lines"; every "mapping line" encodes one row in a keyboard (in one or several layouts). (But the make up of rows of this keyboard may be purely imaginary; it is normal to have a "keyboard" with one row of numbers 0...9.) Configuration settings specify how many lines are per row, and how many layers are encoded by every line, and what are the names of these layers:

 visual_rowcount        # how many config lines per row of keyboard
 visual_per_row_counts  # Array of length visual_rowcount
 visual_prefixes        # Array of chars; <= visual_rowcount (miss=SPACE)
 prefix_repeat          # How many times prefix char is repeated (n/a to SPACE)
 in_key_separator       # If several layers per row, splits a key-descr
 layer_names            # Where to put the resulting keys array
 in_key_separator2      # If one of entries is longer than 1 char, join by this 
                                # (optional)

Each line consists of a prefix (which is ignored except for sanity checking), and whitespace-separated list of key descriptions. (Whitespace followed by a combining character is not separating.) Each key description is split using in_key_separator into slots, one slot per layout. (The leading in_key_separator is not separating.) Each key/layout description consists of one or two entries. An entry is either two dashes -- (standing for empty), or a hex number of length >=4, or a string. (A hex numbers must be separated by . from neighbor word characters.) A loner character which has a different uppercase is auto-replicated in uppercase (more precisely, titlecase) form. Missing or empty key/layout description gives two empty entries (note that the leading key/layout description cannot be empty; same for "the whole key description" - use the leading --.

If one of the entries in a slot is a string of length ≥ 2, one must separate the entries by in_key_separator2. Likewise, if a slot has only one entry, and it is longer than 1 char, it must be started or terminated by in_key_separator2.

To simplify BiDi keyboards, a line may optionally be prefixed with the LRO/RLO character; if so, it may optionally be ended by spaces and the PDF character. For compatibility with other components, layer names should not contain characters +()[].

Inclusion of .klc files

Instead of including a .klc file (or its part) verbatim in a visual section, one can make a section DEADKEYS/NAME/name1/nm2 with a key klc_filename. Filename will be included and parsed as a DEADKEYS visual section (with name DEADKEYS/name1/nm2???). (Currently only UTF-16 files are supported.)


A metadata entry is either a string, or an array. A string behaves as if were an array with the string repeated sufficiently many times. Each personality defines MetaData_Index which chooses the element of the arrays. The entries


should be defined in the personality section, or above this section in the configuration tree. (Used when output Windows .klc files.)

Optional metadata currently consists only of VERSION key (the protocol version; hardwired now as 1.0).

Layer/Face/Prefix-key Recipes

The sections layer_recipes and face_recipes contain instructions how to build Layers and Faces out of simpler elements. Similar recipes appear as values of DeadKey_* entries in a face. Such a "recipe" is executed with parameters: a base face name, a layer number, and a prefix character (the latter is undefined when the recipe is a layer recipe or face recipe). (The recipe is free to ignore the parameters; for example, most recipes ignore the prefix character even when they are "prefix key" recipes.)

The recipes and the visual sections are the most important components of the description of a keyboard group.

To construct layers of a face, a face recipe is executed several times with different "layer number" parameter. In contrast, in simplest cases a layer recipe is executed once. However, when the layer is a part of a compound ("parent") recipe, it inherits the "parameters" from the parent. In particular, it may be executed several times with different face name (if used in different faces), or with different layer number (if used - explicitly or explicitly - in different layer slots; for example, Mutator(LayerName) in a face/prefix-key recipe will execute the LayerName recipe separately for all the layer numbers; or one can use Layers(Empty+LayerName) together with Layers(LayerName+Other)). Depending on the recipe, these calls may result in the same layout of the resulting layers, or in different layouts.

A recipe may be of three kinds: it is either a "first comer wins" which is a space-separated collection of simpler recipes, or SELECTOR(COMPONENTS), or a "mutator": MUTATOR(BASE) or just MUTATOR. All recipes must be ()-balanced and []-balanced; so must be the MUTATOR; in turn, the BASE is either a layer name, or another recipe. A layer name must be defined either in a visual KBD section, or be a key in the layer_recipes section (so it should not have +()[] characters), or be the literal Empty. When MUTATOR(BASE) is processed, first, the resulting layer(s) of the BASE recipe are calculated; then the layer(s) are processed by the MUTATOR (one key at a time).

The most important SELECTOR keywords are Face (with argument a face name, defined either via a faces/FACENAME section, or via face_recipes) and Layers (with argument of the form LAYER_NAME+LAYER_NAME+..., with layer names defined as above). Both select the layer (out of a face, or out of a list) with number equal to the "layer number parameter" in the context of the recipe. The FlipLayers builder is similar to Face, but chooses the "other" layer ("cyclically the next" layer if more than 2 are present).

The other selectors are Self, LinkFace and FlipLayersLinkFace; they operate on the base face or face associated to the base face.

The simplest forms of MUTATORS are Id, lc, uc, ucfirst, Empty (note that uc/lc/ucfirst return undefined when case-conversion results in no change; use maybe_uc/maybe_lc/maybe_ucfirst if one wants them to behave as Perl operators). Recall that a layer is nothing more than a structure associating a pair "unshifted/shifted character" to the key number, and that these characters may be undefined. These simplest mutators modify these characters independently of their key numbers and shift state (with Empty making all of them undefined). Similar user-defined simple mutators are ByPairs[PAIRS]; here PAIRS consists of pairs "FROM TO" of characters (with optional spaces between pairs); characters not appearing as FROM become undefined by ByPairs. (As usual, characters may be replaced by hex numbers with 4 or more hex digits; separate the number from a neighboring word character by . [dot].)

All mutators must have a form WORD or WORD[PARAMETERS], with PARAMETERS (),[]-balanced. Other simple mutators are dectrl (converts control-char [those between 0x00 and 0x1f] to the corresponding [uppercase] character), ShiftFromTo[FROM,TO] (adds a constant to the [numerical code of the] input character so that FROM becomes TO), SelectRX[PERL_REGEXP] (keeps input characters which match, converts everything else to undefined), FromTo[LAYER_FROM,LAYER_TO] (similar to ByPairs, but pairs all characters in the layers based on their position), DefinedTo[CHAR] (all defined characters are converted to CHAR).

The mutator Imported[NAME] is similar to <ByPairs>, but takes the .klc-style visual DEADKEYS/NAME section as the description of the mutation. NAME may be followed by a character as in NAME,CHAR; if not, CHAR is the prefix key from the recipe's execution parameters.

The simple mutator ByPairs has flavors: one can append Prefix or InvPrefix to the name, and the resulting characters become prefix keys (the “AltGr-inverted” prefix followed by CHAR behaves as non-inverted prefix followed by AltGr-CHAR).

Some mutators pay attention not only to what the character is, but how it is accessible on the given key: such are FlipShift, FlipLayers, FromToFlipShift[LAYER_FROM,LAYER_TO]. Some other mutators also take into account how the key is positioned with respect to the other keys.

ByColumns[CHARS] assigns a character to a particular column of the keyboard. Which keys are in which columns is governed by how the corresponding visual layer is formatted (shifted to the right by keyline_offsets array of the visual layer). This visual layer is one associated to the face by the geometry_via_layer key (and the face is the parameter face of the mutator). CHARS is a comma-separated list; empty positions map to the undefined character.

ByRows[MUTATORS] chooses a mutator based on the row of the keyboard. On the top row, it is the first mutator which is chosen, etc. The list MUTATORS is separated by /// surrounded by whitespace.

The mutator InheritPrefixKeys[FACE_FROM] converts some non-prefix characters to prefix characters; the conversion happens if the argument of the mutator coincides with what is at the corresponding position in FACE_FROM, and this position contains a prefix character. (Nowadays this mutator is not very handy — most of its uses may be accomplished by having inheritable prefix characters in appropriate faces.)

The mutators NotId(BASEFACE FACES), NotSameKey(BASEFACE FACES) process their argument in a special way: the characters in FACES which duplicated the characters present (on the same key, and possibly with the same modifiers) in BASEFACE are ignored. The remaining characters are combined “as usual” with “the first comer wins”.

The most important mutator is Mutate (and its flavors). (See "The Mutate[RULES] mutator".)

Note that Id(LAYERNAME) is similar to a selector; it is the only way to insert a layer without a selector, since a bareword is interpreted as a MUTATOR; Id(LAYERNAME) is a synonym of Layers(LAYERNAME+LAYERNAME+...) (repeated as many times as there are layers in the parameter "base face").

The recipes in a space-separated list of recipes ("first comer wins") are interpreted independently to give a collection of layers to combine; then, for every key numbers and both shift states, one takes the leftmost recipe which produces a defined character for this position, and the result is put into the resulting layer.

Keep in mind that to understand what a recipe does, one should trace its description right-to-left order: for example, ByPairs[.:](FlipLayers) creates a layout where : is at position of ., but on the second [=other] layer (essentially, if the base layout is the standard one, it binds the character : to the keypress AltGr-.).

To simplify formatting of .kbdd files, a recipe may be an array reference. The string may be split on spaces, or split after comma or |.

The Mutate[RULES] mutator

The essense of Mutate is to have several mutation rules and choose the best of the results of application of these rules. Grouping the rules allows one a flexible way to control what the best actually means. The rules may be separated by comma, by |, or by ||| (interchangeable with ||||).

In the simplest case of grouping, RULES form a |-separated list, and each group consists of one rule. Then the best result is one coming from an earlier rule. The groups are separated by |, and the rules inside the group are separated by comma; if more than one rule appears in a group, a different kind of competition appears (inside the group).

The quality of the generated characters is a list UNICODE_AGE, HONEST, UNICODE_BLOCK, IN_CASE_PAIR, FROM_NON_ALTGR_POSITION with lexicographical order (the earlier element is stronger that ones after it). Here HONEST describes whether a character is generated by Unicode compositing (versus “compatibility compositing” or other “artificially generated” mogrifiers); the older age wins, as well as honest compositing, earlier Unicode blocks, as well as case pairs and characters from non-AltGr-positions. (Experience shows that these rules have a pretty good correlation with being “more suitable for human consumption”.)

Moreover, quality in case-pairs is equalized by assigning the strongest quality of two. Such pairs are always considered “tied together” when they compete with other characters. (In particular, if a single character with higher quality occupies one of Shifted/Unshifted positions, a case pair with lower quality is completely ignored; so the “other” position may be taken by a single character with yet lower quality.)

In addition, the characters which lost the competition for non-AltGr-positions are considered again on AltGr-positions. (With boosted priority compared to mutated AltGr-characters; see above.)

This mutator comes in several flavors: one can append to its name SpaceOK/Hack/DupsOK/32OK (in this order). Unless SpaceOK is specified, it will not modify characters on a key which produces SPACE when used without modifiers. Unless 32OK is specified, it will not produce Unicode characters after 0xFFFF (the default is to follow the brain-damaged semantic of prefix keys on Windows). Unless DupsOK is specified, the result is optimized by removing duplicates (per key) generated by application of RULES. With the Hack modifier, the generated characters are not counted as “obtained by logical rules” when statistics for the generated keyboard layout are calculated.

Linked prefixes

On top of what is explained above, there is a way to arrange “linking” of two prefix keys; this linking allows characters which cannot be fit on one (prefixed) key to “migrate” to unassigned positions on the otherwise-prefixed key. (This is similar to migration from non-AltGr-position to AltGr-position.) This is achieved by using mutator rules of the following form:

  primary       =               +PRE-GROUPS1|||SHARED||||POST-GROUPS1
  secondary     = PRE-GROUPS2||||PRE-GROUPS1|||SHARED||||POST-GROUPS2

Groups with digits are not shared (specific to a particular prefix); SHARED is (effectively) reverted when accessed from the secondary prefix; for the secondary key, the recipies from SHARED which were used in the primary key are removed from SHARED, and are appended to the end of POST-GROUPS2; the PRE-GROUPS1 are skipped when finding assignments for the secondary prefix.

In the primary recipe, ||| and |||| are interchangeable with |. Moreover, if POST-GROUPS2 is empty, the secondary recipe should be written as

  secondary     = PRE-GROUPS2|||PRE-GROUPS1|||SHARED

if PRE-GROUPS1 is empty, this should be written as one of

  secondary     = PRE-GROUPS2|||SHARED
  secondary     = PRE-GROUPS2||||SHARED
  secondary     = PRE-GROUPS2||||SHARED||||POST-GROUPS2

These rules are to allow macro-ization of the common parts of the primary and secondary recipe. Put the common parts as a value of the key Named_DIA_Recipe__*** (here *** denotes a word), and replace them by the macro <NAMED-***> in the recipes.

Implementation: the primary key recipe starts with the + character; it forces interpretation of ||| and |||| as of ordinary |.

If not primary, the top-level groups are formed by |||| (if present), otherwise by |||. The number of top-level groups should be at most 3. The second of ||||-groups may have at most 2 |||-groups; there should be no other subdivision. This way, there may be up to 4 groups with different roles.

The second of 3 toplevel |||-groups, or the first of two sublevel |||-groups is the “skip” group. The last of two or three toplevel |||-groups (or of sublevel |||-groups, or the 2nd toplevel ||||-group without subdivisions) is the inverted group; the 3rd of toplevel ||||-groups is the “extra” group.

“Penalize/prohibit” lists start anew in every top-level group.

Atomic mutators rules

As explained above, the individual RULES in Mutate[RULES] may be separated by , or |, or ||| or ||||. Such an individual rule is a combination of atomic rules combined by + operators, and/or preceded by - prefix (with understanding that +- must be replaced by --). The prefix - means inversion of the rule; the operator + is the composition of the rules.

Example: the atomic rule <super> converts its input character into its superscript forms (if such forms exist; for example, a may be converted to or ª). The atomic rules lc, uc, ucfirst behave the same as the corresponding MUTATORs. The atomic rule dectrl converts a control-character to the corresponding “uppercase” character: ^A is converted to A, and ^\ is converted to \. (The last 4 rules cannot be inverted by -.)

The composition is performed (as usual) from right to left. Example: the indivial rule <super>+lc+dectrl converts ^A to or ª.

In addition to rules listed above, the atomic rules may be of the following types:

Input substitution in atomic rules

TBC ..........................................

The Mutate2Self mutator

TBC ..............................

Pseudo-mutators for generation of documentation

A few mutators do not introduce any characters (in other words, they behave as Empty) but are used for their side effects: in prefix-key recipes, PrefixDocs[STRING] introduces documentation of what the prefix key is intended for. Likewise, HTML_classes[HOW] allows adding CSS classes to highlight parts of HTML output generated by this module, the parts corresponding to selected characters in a face.

HOW is a comma-separated list, every triple in the list being WHERE,HTML_CLASS,CHARACTERS. WHERE is one of k/K (which add formatting to the key containing one of the CHARACTERS) or c/C (which add formatting to an individual character displayed on the key), one can add a digit to WHERE to limit to a particular layer in the face (useful when a character appears several times in a face). The lower-case variants select characters basing on the base face of a key. One can also append =CONTEXT to WHERE, then the class is added only if CONTEXT appears as one of the options for the HTML output generator.

The CSS rules generated by this module support several classes directly; the rest should be supported by the user-supplied rules. The classes with existing support are: on keys

  to_w from_w                           # generate arrows between keys
  from_nw from_ne to_nw to_ne           # generate arrows between keys; will yellow-outline
  pure                                  #       unless combined with this
  red-bg green-bg blue-bg               # tint the key as the whole (as background)

On characters

  very-special need-learn may-guess     # provide green/brown/yellow-outlines
  special                               # provide blue outline (thick unless combined with 
  thinspecial                           #                   <-- this)

Extra CSS classes for documentation

In additional, several CSS classes are auto-generated basing on Unicode properties of the character. TBC ........................

Debugging mutators

If the bit 0x40 of the environment variable UI_KEYBOARDLAYOUT_DEBUG (decimal or 0xHEX) is set, debugging output for mutators is enabled:

  r ║ ║   ┆ ║ ṙ ṛ ┆ ║ ║ ║ ║ ⓡ ┆
    ║ ║   ┆ ║ Ṙ Ṛ ┆ ║ ║ ║ ║ Ⓡ ┆
    ║ ║ ặ ┆ ║     ┆ ║ ║ ║ ║   ┆
    ║ ║ Ặ ┆ ║     ┆ ║ ║ ║ ║   ┆
  Extracted [ …list… ] deadKey=00b0

The output contains a line per character assigned to the keyboard key (if there are 2 layers, each with lc/uc variants, there are 4 lines); empty lines are omitted. The first column indicates the base character (lc of the 1st layer) of the key; the separator indicates |-groups in the mutator. Above, the first group produces no mutations, the second group mutates only the characters in the second layer, and the third group produces two mutations per a character in the first layer. The 7th group is also producing mogrifications on the 1st layer.

The next example clarifies -separator: to the left of it are mogrifications which come in case pairs, to the right are mogrifications where mogrified-lc is not a case pair of mogrified-uc:

  t ║ ║ ᵵ ║ ꞇ ┆ ʇ ║   ┆ ║
    ║ ║   ║ Ꞇ ┆ ᴛ ║   ┆ ║
    ║ ║   ║   ┆   ║ ꝧ ┆ ║
    ║ ║   ║   ┆   ║ Ꝧ ┆ ║
  Extracted [ …list… ] deadKey=02dc

In this one, separates mogrifications with different priorities (based on Unicode ages, whether the atomic mutator was compatibility/synthetic one, and the Unicode block).

  / ║ ║ ║ ║ ║   │ ∴   ║ ║
    ║ ║ ║ ║ ║   │ ≘ ≗ ║ ║
    ║ ║ ║ ║ ║ / │ ⊘   ║ ║
  Extracted [ …list… ] deadKey=00b0

For secondary mogrifiers, where the distinction between ||| and | matters, some of the -separators are replaced by . Additionally, there are two rounds of extraction: first the characters corresponding to the primary mogrifier are TMP-extracted (from the groups PRE-GROUPS1, COMMON); then what is the extracted from COMMON is put back at the effective end (at the end of POST-GROUPS2, or, if no such, at the beginning of COMMON):

  t ║ ║ ᵵ ┃ ┃ ʇ │   │ ꞇ ┆ ║
    ║ ║   ┃ ┃   │ ᴛ │ Ꞇ ┆ ║
    ║ ║   ┃ ┃   │   │ ꝧ ┆ ║
    ║ ║   ┃ ┃   │   │ Ꝧ ┆ ║
  TMP Extracted: <…list…> from layers 0 0 | 0 0
  t ║ ║ ᵵ ┃ ꞇ ┆ ʇ ┋ ┃ ┆ │ ┆ │   ┆ ║
    ║ ║   ┃ Ꞇ ┆ ᴛ ┋ ┃ ┆ │ ┆ │   ┆ ║
    ║ ║   ┃   ┆   ┋ ┃ ┆ │ ┆ │ ꝧ ┆ ║
    ║ ║   ┃   ┆   ┋ ┃ ┆ │ ┆ │ Ꝧ ┆ ║
  Extracted [ …list… ] deadKey=02dc

In the second part of the debugging output, the part of common which is put back is separated by .

When bit 0x80 is set, much more lower-level debugging info is printed. The arrays at separate depth mean: group number, priority, not-cased-pair, layer number, subgroup, is-uc. When bit 0x100 is set, the debugging output for combining atomic mutators is enabled.


A personality NAME is defined in the section faces/NAME. (NAME may include slashes - untested???)

An array layers gives the list of layers forming the face. (As of version 0.03, only 2 layers are supported.) The string LinkFace is a face.........


In section Substitutions one defines composition rules which may be used on par with composition rules extracted from Unicode Character Database. An array FOO is converted to a hash accessible as <subst-FOO> from a Diacritic filter of satellite face processor. An element of the the array must consist of two characters (the first is mapped to the second one). If both characters have upper-case variants, the translation between these variants is also included.

Classification of diacritics

The section Diacritics contains arrays each describing a class of diacritic marks. Each array may contain up to 7 elements, each consising of diacritic marks in the order of similarity to the "principal" mark o fthe array. Combining characters may be preceded by horizontal space. Elements should contain:

 Surrogate chars; 8bit chars; Modifiers
 Modifiers below (or above if base char is below)
 Vertical (or Comma-like or Doubled or Dotlike or Rotated or letter-like) Modifiers
 Prime-like or Centered modifiers
 Combining below (or above if base char is below)
 Vertical combining and dotlike Combining

These lists determine what a Diacritic2Self filter of satellite face processor will produce when followed by whitespace characters (possibly with modifiers) SPACE ENTER TAB BACKSPACE. (So, if .kbdd file requires this) this determines what diacritic prefix keys produce.

Naming prefix keys ^

Section DEADKEYS defines naming of prefix keys. If not named there (or in processed .klc files), the PrefixDocs property will be used; if none, Unicode name of the character will be used.

Keyboards: on ease of access ^

Let's start with trivialities: different people have different needs with respect to keyboard layouts. For a moment, ignore the question of the repertoir of characters available via keyboard; then the most crucial distinction corresponds to a certain scale. In absense of a better word, we use a provisional name "the required typing speed".

One example of people on the "quick" (or "rabid"?) pole of this scale are people who type a lot of text which is either "already prepared", or for which the "quality of prose" is not crucial. Quite often, these people may type in access of 100 words per minute. For them, the most important questions are of physical exhaustion from typing. The position of most frequent letters relative to the "rest" finger position, whether frequently typed together letters are on different hands (or at least not on the same/adjacent fingers), the distance fingers must travel when typing common words, how many keypresses are needed to reach a letter/symbol which is not "on the face fo the keyboard" - their primary concerns are of this kind.

On the other, "deliberate", pole these concerns cease to be crucial. On this pole are people who type while they "create" the text, and what takes most of their focus is this "creation" process. They may "polish their prose", or the text they write may be overburdened by special symbols - anyway, what they concentrate on is not typing itself.

For them, the details of the keyboard layout are important mostly in the relation to how much they distract the writer from the other things the writer is focused on. The primary question is now not "how easy it is to type this", but "how easy it is to recall how to type this". The focus transfers from the mechanics of finger movements to the psycho/neuro/science of memory.

These questions are again multifaceted: there are symbols one encounters every minute; after you recall once how to access them, most probably you won't need to recall them again - until you have a long interval when you do not type. The situation is quite different with symbols you need once per week - most probably, each time you will need to call them again and again. If such rarely used symbols/letters are frequenct (since many of them appear), it is important to have an easy way to find how to type them; on the other hand, probably there is very little need for this way to be easily memorizable. And for symbols which you need once per day, one needs both an easy way to find how to type them, and the way to type them should better be easily memorizable.

Now add to this the fact that for different people (so: different usage scenarios) this division into "all the time/every minute/every day/every week" categories is going to be different. And one should not forget important scenario of going to vacation: when you return, you need to "reboot" your typing skills from the dormant state.

On the other hand, note that the questions discussed above are more or less orthogonal: if the logic of recollection requires ω to be related in some way to the W-key, then it does not matter where the W-key is on the keyboard - the same logic is applicable to the QWERTY base layou t, or BÉPO one, or Colemak, or Dvorak. This module concerns itself only with the questions of "consistency" and the related question of "the ease of recall"; we care only about which symbols relate to which "base keys", and do not care about where the base key sit on the physical keyboard.

NOTE: the version 0.01 of this module supports only the standard US layout of the base keys.

Now consider the question of the character repertoir: a person may need ways to type "continuously" in several languages; in addition to this, there may be a need to occasionally type "standalone" characters or symbols outside the repertoir of these languages. Moreover, these languages may use different scripts (such as Polish/Bulgarian/Greek/Arabic/Japanese), or may share a "bulk" of their characters, and differ only in some "exceptional letters". To add insult to injury, these "exceptional letters" may be rare in the language (such as ÿ in French or à in Swedish) or may have a significant letter frequency (such as é in French) or be somewhere in between (such as ñ in Spanish).

And the non-language symbols do not need to be the math symbols (although often they are). An Engish-language discussion of etimology at coffee table may lead to a need to write down a word in polytonic greek, or old norse; next moment one would need to write a phonetic transcription in IPA/APA symbols. A discussion of keyboard layout may involve writing down symbols for non-character keys of the keyboard. A typography freak would optimize a document by fine-tuned whitespaces. Almost everybody needs arrows symbols, and many people would use box drawing characters if they had a simple access to them.

Essentially, this means that as far as it does not impacts other accessibility goals, it makes sense to have unified memorizable access to as many symbols/characters as possible. (An example of impacting other aspects: MicroSoft's (and IBM's) "US International" keyboards steal characters `~'^": typing them produces "unexpected results" - they are deadkeys. This significantly simplifies entering characters with accents, but makes it harder to enter non-accented characters.)

One of the most known principles of design of human-machine interaction is that "simple common tasks should be simple to perform, and complicated tasks should be possible to perform". I strongly disagree with this principle - IMO, it lacks a very important component: "a gradual increase in complexity". When a certain way of doing things is easy to perform, and another similar way is still "possible to perform", but on a very elevated level of complexity, this leads to a significant psychological barrier erected between these ways. Even when switching from the first way to the other one has significant benefits, this barrier leads to self-censorship. Essentially, people will ignore the benefits even if they exceed the penalty of "the elevated level of complexity" mentioned above. And IMO self-censorship is the worst type of censorship. (There is a certain similarity between this situation and that of "self-fulfilled prophesies". "People won't want to do this, so I would not make it simpler to do" - and now people do not want to do this...)

So I would add another clause to the law above: "and moderately complicated tasks should remain moderately hard to perform". What does it tell us in the situation of keyboard layout? One can separate several levels of complexity.


There should be some "base keyboards": keyboard layouts used for continuous typing in a certain language or script. Access from one base keyboard to letters of another should be as simple as possible.

By parts:

If a symbol can be thought of as a combination of certain symbols accessible on the base keyboard, one should be able to "compose" the symbol: enter it by typing a certain "composition prefix" key then the combination (as far as the combination is unambiguously associated to one symbol).

The "thoughts" above should be either obvious (as in "combining a and e should give æ") or governed by simple mneumonic rules; the rules should cover as wide a range as possible (as in "Greek/Coptic/Hebrew/Russian letters are combined as G/C/H/R and the corresponding Latin letter; the correspondence is phonetic, or, in presence of conflicts, visual").

Quick access:

As many non-basic letters as possible (of those expected to appear often) should be available via shortcuts. Same should be applicable to starting sequences of composition rules (such as "instead of typing StartCompose and ' one can type AltGr-').

Smart access

Certain non-basic characters may be accessible by shortcuts which are not based on composition rules. However, these shortcuts should be deducible by using simple mneumonic rules (such as "to get a vowel with `-accent, type AltGr-key with the physical keyboard's key sitting below the vowel key").


If everything else fails, the user should be able to enter a character by its Unicode number (preferably in the most frequently referenced format: hexadecimal).

NOTE: This does not seem to be easily achievable, but it looks like a very nifty UI: a certain HotKey is reserved (e.g., AltGr-AppMenu); when it is tapped, and a character-key is pressed (for example, B) a menu-driven interface pops up where user may navigate to different variants of B, Beta, etc - each of variants with a hotkey to reach NOW, and with instructions how to reach it later from the keyboard without this UI.

Also: if a certain timeout passes after pressing the initial HotKey, an instruction what to do next should appear.

Here are the finer points elaborating on these levels of complexity:

  1. It looks reasonable to allow "fuzzy mneumonic rules": the rules which specify several possible variants where to look for the shortcut (up to 3-4 variants). If/when one forgets the keying of the shortcut, but remembers such a rule, a short experiment with these positions allows one to reconstruct the lost memory.
  2. The "base keyboards" (those used for continuous typing in a certain language or script) should be identical to some "standard" widely used keyboards. These keyboards should differ from each other in position of keys used by the scripts only; the "punctuation keys" should be in the same position. If a script B has more letters than a script A, then a lot of "punctuation" on the layout A will be replaced by letters in the layout B. This missing punctuation should be made available by pressing a modifier (AltGr? compare with MicroSoft's Vietnamese keyboard's top row).

  3. If more than one base keyboard is used, there must be a quick access: if one needs to enter one letter from layout B when the active layout is A, one should not be forced to switch to B, type the letter, then switch back to A. It must be available on "Quick_Access_Key letter".

  4. One should consider what the Quick_Access_Key does when the layouts A and B are identical on a particular key. One can go with the "Occam's razor" approach and make Quick_Access_Key the do-nothing identity map. Alternatively, one can make it access some symbols useful both for script A and script B. It is a judgement call.

    Note that there is a gray area when layouts A and B are not identical, but a key K produces punctuation in layout A, and a letter in layout B. Then when in layout B, this punctuation is available on AltGr-key, so, in principle, Quick_Access_Key would duplicate the functionality of AltGr. Compare with "there is more than one way to do it" below; remember that OS (or misbehaving applications) may make some keypresses "unavailable". I feel that in these situations, having duplication is a significant advantage over "having some extra symbols available".

  5. Paired symbols (such as such as ≤≥, «», ‹›, “”, ‘’ should be put on paired keyboard's keys: <> or [] or ().

  6. "Directional symbols" (such as arrows) should be put either on numeric keypad or on a 3×3 subgrid on the letter-part of the keyboard (such as QWE/ASD/ZXC). (Compare with [broken?] implementation in Neo2.)

  7. for symbols that are naturally thought of as sitting in a table, one can create intuitive mapping of quite large tables to the keyboard. Split each key in halves by a horizontal line, think of Shift-key as sitting in the top half. Then ignoring `~ key and most of punctuation on the right hand side, keyboard becomes an 8×10 grid. Taking into account AltGr, one can map up to 8×10×2 (or, in some cases, 8×20!) table to a keyboard.

    Example: Think of IPA consonants.

  8. Cheatsheets are useful. And there are people who are ready to dedicate a piece of their memory to where on a layout is a particularly useful to them symbol. So even if there is no logical position for a certain symbol, but there is an empty slot on layout, one should not hesitate in using this slot.

    However, this will be distractive to people who do not want to dedicate their memory to "special cases". So it makes sense to have three kinds of cheatsheets for layouts: one with special cases ignored (useful for most people), one with all general cases ignored (useful for checks "is this symbol available in some place I do not know about" and for memorization), and one with all the bells and whistles.

  9. "There is more than one way to do it" is not a defect, it is an asset. If it is a reasonable expectation to find a symbol X on keypress K', and the same holds for keypress K'' and they both do not conflict with other "being intuitive" goals, go with both variants. Same for 3 variants, 4 - now you get my point.

    Example: The standard Russian phonetic layout has Ё on the ^-key; on the other hand, Ё is a variant of Е; so it makes sense to have Ё available on AltGr-Е as well. Same for Ъ and Ь.

  10. Dead keys which are "abstract" (as opposed to being related to letters engraved on physical keyboard) should better be put on modified state of "zombie" keys of the keyboard (SPACE, TAB, CAPSLOCK, MENU_ACCESS).

    NOTE: Making Shift-Space a prefix key may lead to usability issues for people used to type CAPITALIZED PHRASES by keeping Shift pressed all the time. As a minimum, the symbols accessed via Shift-SPACE key should be strikingly different from those produced by key so that such problems are noted ASAP. Example: on the first sight, producing NO-BREAK SPACE on Shift-Space Shift-Space or Shift-Space Space looks like a good idea. Do not do this: the visually undistinguishable NO-BREAK SPACE would lead to significantly hard-to-debug problems if it was unintentional.

Explanation of keyboard layout terms used in the docs ^

The aim of this module is to make keyboard layout design as simple as possible. It turns out that even very elaborate designs can be made quickly and the process is not very error-prone. It looks like certain venues not tried before are now made possible; at least I'm not aware of other attempts in this direction. One can make layouts which can be "explained" very concisely, while they contain thousand(s) of accessible letters.

Unfortunately, being on unchartered territories, in my explanations I'm forced to use home-grown terms. So be patient with me... The terms are keyboard group, keyboard, face and layer. (I must compare them with what ISO 9995 does:

In what follows, the words letter and character are used interchangeably. A key means a physical key on a keyboard clicked (possibly together with one of modifiers Shift, AltGr - or, rarely Control. The key AltGr is either marked as such, or is just the "right" Alt key; at least on Windows it can be replaced by Control-Alt. A prefix key is a key tapping which does not produce any letter, but modifies what the next keypress would do (sometimes it is called a dead key; in ISO 9995 terms, it is probably a latching key).

A plain layer is a part of keyboard layout accessible by using only non-prefix keys (possibly in combination with Shift); likewise, additional layers are parts of layout accessible by combining the non-prefix keys with Shift (if needed) and with a particular combination of other modifiers (AltGr or Control). So there may be up to 2 additional layers: the AltGr-layer and Control-layer.

On the simplest layouts, such as "US" or "Russian", there is no prefix keys - but this is only feasible for languages which use very few characters with diacritic marks. However, note that most layouts do not use Control-layer - it is stated that this might be subject to problems with system interaction.

The primary face consists of the plain and additional layers of a keyboard; it is the part of layout accessible without switching "sticky state" and without using prefix keys. There may be up to 3 layouts (Primary, AltGr, Control) per face (on Windows). A secondary face is a face exposed after pressing a prefix key.

A personality is a collection of faces: the primary face, plus one face per a defined prefix-key. Finally, a keyboard group is a collection of personalities (switchable by CapsLock and/or personality change hotkeys like Shift-Alt) designed to work smoothly together.

EXAMPLE: Start with a very elaborate (and not yet implemented, but feasible with this module) example. A keyboard group may consist of phonetically matched Latin and Cyrillic personalities, and visually matched Greek and Math personalities. Several prefix-keys may be shared by all 4 of these personalities; in particular, there would be 4 prefix-keys allowing access to primary faces of these 4 personalities from other personalities of the group. Also, there may be specialised prefix-key tuned for particular need of entering Latin script, Cyrillic script, Greek script, and Math.

Suppose that there are 8 specialized Latin prefix-keys (for example, name them


although in practice each one of them may do more than the name suggests). Then Latin personality will have the following 13 faces:


NOTE: Here Latin-Primary is the face one gets when one presses the Access-Latin prefix-key when in Latin mode; it may be convenient to define it to be the same as Primary - or maybe not. For example, if one defines it to be Greek-Primary, then this prefix-key has a convenient semantic of flipping between Latin and Greek modes for the next typed character: when in Latin, Latin-PREFIX-KEY a would enter α, when in Greek, the same keypresses [now meaning "Latin-PREFIX-KEY α"] would enter "a".

Assume that the layout does not use the Control modifier. Then each of these faces would consists of two layers: the plain one, and the AltGr- one. For example, pressing AltGr with a key on Greek face could add diaeresis to a vowel, or use a modified ("final" or "symbol") "glyph" for a consonant (as in σ/ς θ/ϑ). Or, on Latin face, AltGr-a may produce æ. Or, on a Cyrillic personality, AltGr-я (ya) may produce ѣ (yat').

Likewise, the Greek personality may define special prefix-keys to access polytonic greek vowels. (On the other hand, maybe this is not a very good idea - it may be more useful to make polytonic Greek accessible from all personalities in a keyboard group. Then one is able to type a polytonic Greek letter without switching to the Greek personality.)

With such a keyboard group, to type one Greek word in a Cyrillic text one would switch to the Greek personality, then back to Cyrillic; but when all one need to type now is only one Greek letter, it may be easier to use the "Greek-PREFIX-KEY letter" combination, and save switching back to the Cyrillic personality. (Of course, for this to work the letter should be on the primary face of the Greek personality.)


Looks too complicated? Try to think about it in a different way: there are many faces in a keyboard group; break them into 3 "onion rings":

CORE faces

one can "switch to a such a face" and type continuously using this face without pressing prefix keys. In other words, these faces can be made "active".

When another face is active, the letters in these faces are still accessible by pressing one particular prefix key before each of these letters. This prefix key does not depend on which core face is currently "active". (This is the same as for univerally accessible faces.)

Universally accessible faces

one cannot "switch to them", however, letters in these faces are accessible by pressing one particular prefix key before this letter. This prefix key does not depend on which core face is currently "active".

satellite faces

one cannot "switch to them", and letters in these faces are accessible from one particular core face only. One must press a prefix key before every letter in such faces.

For example, when entering a mix of Latin/Cyrillic scripts and math, it makes sense to make the base-Latin and base-Cyrillic faces into the core; it is convenient when (several) Math faces and a Greek face can be made universally accessible. On the other hand, faces containing diacritized Latin letters and diacritized Cyrillic letters should better be made satellite; this avoids a proliferation of prefix keys which would make typing slower.

Access to diacritic marks ^

The logic: prefix keys are either 8-bit characters with high bit set, or if none with the needed glyph, they are "spacing modifier letters" or "spacing clones of diacritics". And if you type something after them, you can get other modifier letters and combining characters: here is the logic of this:

The second press

The principal combining mark.

Surrogate for the diacritic

(either " or '): corresponding "prime shape"-modifier character


The modifier character itself.


Modifier letter (the first one if diacritic is 8-bit, the second one otherwise.

Some stats on prefix keys: ISO 9995-3 uses 26 prefix keys for diacritics; bépo uses 20, while EurKey uses 8. On the other end of spectrum, there are 10 US keyboard keys with "calculatable" relation to Latin diacritics:

  `~^-'",./? --- grave/tilde/hat/macron/acute/diaeresis/cedilla/dot/stroke/hook-above

To this list one may add a "calculatable" key $ as the currency prefix; on the other hand, one should probably remove ? since AltGr-? should better be "set in stone" to denote ¿. If one adds Greek, then the calculatable positions for aspiration are on [ ] (or on ( )). Of widely used Latin diacritics, this leaves ring/hacek/breve/horn/ogonek/comma (and doubled grave/acute).

CAVEATS for BÉPO keyboard:

Non-US keycaps: the key "a" still uses (VK_)A, but its scancode is now different. E.g., French's A is on 0x10, which is US's Q. Our table of scancodes is currently hardwired. Some pictures and tables are available on


Useful tidbits from Unicode mailing list (unsorted) ^

On keyboards

MS keyboard (wrong?)

Symbols for Keyboard keys:
     “Menu key” variations:
     Role of ISO/IEC 9995, switchable keycaps

On the other hand, having access to text only math symbols makes it possible to implement it in computer languages, making source code easier to read.

Right now, I feel there is a lack of keyboard maps. You can develop them on your own, but that is very time consuming.

Keyboards - agreement (5 scripts at end)

Need for a keyboard, keyman examples; why "standard" keyboards are doomed

History of Unicode

Unicode in 1889

Structure of development of Unicode
      I don't have a problem with Unicode. It is what it is; it cannot
      possibly be all things to all people:

Compromizes vs reality

Stability of normalization

Universality vs affordability


w-ring is a stowaway

History of squared pH (and about what fits into ideographic square)

Silly quotation marks: 201b, 201f 
                under "4.6 Apostrophe Semantics Errata"

OHM: In modern usage, for new documents, this character should not be used.

Uppercase eszett ß ẞ

Should not use (roman numerals)

Colors in Unicode names

Xerox and interrobang

Tibetian (history of encoding, relative difficulty of handling comparing to cousins)

Translation of 8859 to 10646 for Latvian was MECHANICAL



Combining power of generative features - implementor's view

Greek and about


Greek letters for non-Greek

Macron and breve in Greek dictionaries


COMBINING GREEK YPOGEGRAMMENI equilibristic (depends on a vowel?)

Latin, Cyrillic, Hebrew, etc

Book Spine reading direction

What is a "Latin" char

Federal vs regional aspects of Latinization (a lot of flak; cp1251)

Yiddish digraphs

Cyrillic Script, Unicode status (+combining)

The IBM 1401 Hebrew Letter Key

GOST 10859

Hebrew char input

Cyrillic soup

How to encode Latin-in-fraktur

The presentation of the existing COMBINING CEDILLA which has three major forms [ȘșȚț and Latvian Ģģ]

Math and technical texts

Missing: .... skew-orthogonal complement

Math Almost-Text encoding
    For me 1/2/3/4 means unambiguously ((1/2)/3)/4, i.e. 1/(2*3*4)

    Unicode mostly encodes characters that are in use or have been
    encoded in other standards. While not semantically agnostic, it is
    much less oriented towards semantic clarifications and
    distinctions than many people might hope for (and this includes
    me, some of the time at least).

Horizontal/vertical line/arrow extensions

Pretty-printing text math

Sub/Super on a terminal

CR symbols

Math layout

Unicode and linguists

Linguists mailing lists

Obsolete IPA[%3Asubhead%3D%2F%28%3Fi%29archaic%2F%3A]+&g=

Teutonista (vowel guide p11, kbd p13)


Spaces, invisible characters, VS

Substitute blank

Representing invisible characters

Ignorable glyphs

HOWTO: (non)dummy VS in fonts


On which base to draw a "standalone" diacritics

Variation sequences


Upside-down text in CSS (remove position?)

Unicode to PostScript

Spacing: English and French

Chicago Manual of Style

Coloring parts of ligatures Implemenations:

Chinese typesetting

@fonts and non-URL URIs

Looking at the future

Why and how to introduce innovative characters

Unicode knows the concept of a provisional property
    If you want to make analogies, however, the ISO ballots constitute
    the *provisional* publication for character code points and names.
        that needs to be available from day one for a character to be
        implementable at all (such as decomp mappings, bidi class,
        code point, name, etc.).

                        - to define decomposition, prepend it

Exciting new letter forms for English,2869/

Proposing new stuff, finding new stuff proposed

A useful set of criteria for encoding symbols is found in Annex H of this document: 


Summary views into CLDR


Classification of Dings (bats etc)

        Escape: 2be9 2b9b
        ARROW SHAFT - various



Diacritics in fonts

Licences (GPL etc) in TV sets

Similar glyphs:

GeoLocation by IP

Per language character repertoir:

Dates/numbers in Unicode

Normalization FAQ


Apostroph as soft sign

Questionner at start of Unicode proposal



CGI and OpenType

Numbers in scripts ;-)

Indicating coverage of the font

Accessing ligatures

Folding characters

Writing systems vs written languages

MS Visual OpenType tables

"Same" character Oacute used for different "functions" in the same text


Sign writing

Writing digits in non-decimal
        Which separator is less ambiguous?  Breve ˘ ? ␣ ?  Inverted ␣ ?

Use to identify a letter:

Perl has problems with unpaired surrogates (whole thread)

Complex fonts (e.g., Indic)

Complex glyphs in Symbola (pre-6.01) font may crash older versions of Windows

Window 7 SP1 improvements

Middle dot is ambiguous

Superscript == modifiers

Translation of Unicode names

Transliteration on passports (see p.IV-48)

Keyboard input on Windows: interaction of applications and the kernel ^

Keyboard input on Windows, Part I: what is the kernel doing?

This is not documented. We try to provide a description which is both as simple as possible, and as complete as possible. (We ignore many important parts: the handling of hot keys [or C-A-Del]), IME, handling of focus switch [Alt-Tab etc], the keyboard filters, widening of virtual keycodes, and LED lights.)

We omit Step 0, when the hardware keyboard drivers (PS/2 or USB) deliver keydown/up(/repeat???) event for scan codes of corresponding keys. (This is a complicated topic, but well-documented.)

  1. The scan codes are massaged (see “Low level scancode mapping” in "SEE ALSO").
  2. The keyboard layout tables map the translated scancode to a virtual keycode. (This may also depend on the “modification column”; see "Far Eastern keyboards on Windows".)
  3. Mythology: the modification keys (Shift, Alt, Ctrl etc) are taken into account.

    What actually happens: any key may act as a modification key. The keyboard layout tables map keycodes to 8-bit masks. (The customary names for lower bits of the mask are KBDSHIFT, KBDCTRL, KBDALT, KBDKANA; two more bits are named KBDROYA and KBDLOYA; two more bits are unnamed.) The keycodes of the currently pressed keys are translated to masks, and these masks are ORed together. (For the purpose of translation to WM_CHAR/etc [done in ToUnicode()/ToUnicodeEx()], the bit KBDKANA may be set also when key VK_KANA was pressed odd number of times; this is controlled by KANALOK flag in a virtual key descriptor [of the key being currently processed] of the keyboard layout tables.)

    The keyboard layout tables translate the ORed mask to a number called “modification column”. (Thess two numbers are completely hidden from applications. The only glint the applications get is in the [useless, since there is no way to map it to anything “real”] result of VkKeyScanEx().])

  4. Depending on the current “modification column”, the virtual keycode of the current key event may be massaged further. (See "Far Eastern keyboards on Windows".) Numpad keycodes depend also on the state of NumLock — provided the keyboard layout table marks them with KBDNUMPAD flag. A few other scancodes may also produce different virtual keycodes in different situations (e.g., Break).

    When KLLF_ALTGR flag is present, fake presses/releases of left Ctrl are generated on presses/releases of right Alt. With keypad presses/releases in presence of VK_SHIFT and NumLock, fake releases/presses of VK_SHIFT are generated.

  5. The message WM_(SYS)KEYDOWN/UP is delivered to the application. If VK_MENU [usually called the Alt key] is down, but VK_CONTROL is not, the event is of SYS flavor (this info is duplicated in lParam. Additionally, for VK_MENU tapping, the UP event is also made SYS — although at this moment VK_MENU is not down!). (The KBDEXT flag [of the scancode] is also delivered to the application.)

    The following steps are applicable only if the application uses “the standard message pump” with TranslateMessage()/DispatchMessage() or uses some equivalent code.

  6. Before the application dispatches WM_(SYS)KEYDOWN/UP to the message handler, TranslateMessage() calls ToUnicode() with wFlags = 0 (unless a popup menu is active; then wFlags = 1 — which disables character-by-number input via numeric KeyPad) and the buffer of 16 UTF-16 code units.
  7. The UTF-16 code units obtained from ToUnicode() are posted via PostMessage(). All the code units but the last one are marked by FAKE_KEYSTROKE flag in lParam. If the initial message was WM_SYSKEYDOWN, the SYS flavor is posted; if ToUnicode() returns a deadkey, the DEAD flavor is posted.

    (The bit ALTNUMPAD_BIT is set/used only for the console handler.)

Keyboard input on Windows, Part II: The semantic of ToUnicode()

The syntax of ToUnicode() is documented, the semantic is not. Here we fix this.

  1. If the bit 0x01 in wFlags is not set, the key event is checked for contributing to character-by-number input via numeric KeyPad. If so, the character is delivered only when Alt is released. (This the only case when KEYUP delivers a character.) Unless the bit 0x02 in wFlags is set, the KEYUP events are not processed any more.
  2. The flag KLLF_LRM_RLM is acted upon, and VK_PACKET is processed.
  3. The keys which are currently down are mapped to the ORed bitmap (see above).
  4. If the key event does not contribute to input-by-number via numeric keypad, and KBDALT is set, and no other bits except KBDSHIFT, KBDKANA are set: then the bit KBDALT is removed from the ORed mask.
  5. If CapLock is active, KBDSHIFT state is flipped in the following cases: either at most KBDSHIFT is set in the bitmap, and CAPLOK is set in the descriptor, or both KBDALT and KBDCTRL are set in the bitmap, and CAPLOKALTGR is set in the descriptor.

    Now the ORed bitmap is converted to the modification column (see above).

  6. The key descriptor for the current virtual keycode is consulted (the “row” of the table). If SGCAPS flag is on, CapsLock is active, and no other bits but KBDSHIFT are set in the bitmap, the row is replaced by the next row.
  7. The entry at the row/column is extracted; if defined, it is either a string (zero or more UTF-16 code units), or a dead key ID (one UTF-16 unit). (Implementation: the ID is taken from the next row of the table.)

    (If the ORed mask corresponds to a valid modification column, but the row does not define the behaviour at this column, and the bit KBDCTRL is set, and no other bits but KBDSHIFT, KBDKANA are set, then an autogenerated character in the range 0x00..0x1f is emitted for virtual keycodes 'A'..'Z' and widened virtual keycodes 0xFF61..0xFF91 (for latter, based on the low bits of translation-to-scancode).

  8. The resulting units are fed to the finite automaton. When the automaton is in 0-state, a fed character unit is passed through, and a fed deadkey ID sets the state of the automaton to this number. In non-0 state, the IDs behave the same as numerically equal character units; the behaviour is described by the keyboard layout tables. The automaton changes the state according to the input; it may also emit a character (= 1 code unit; then it is always reset to 0 state). When “unrecognized input” arrives, the automaton emits the ID and the input, and resets to 0 state.

    (On KEYUP event, the changes to the state of the finite-automaton are ignored. This is only relevant if wFlags has bit 0x02 set.)

  9. After UTF-16 units are passed through the automaton, its output is returned by ToUnicode(). If the automaton is in non-0 state, the state ID becomes the output.

NOTE: MSKLC restricts the length of the string associated to the row/column cell to be at most 4 UTF-16 code units.

NOTE: If the string is “long” (i.e., defined via LIGATURES), when it is fed through the finite automaton, the transitions to non-0 state do not generate deadkey IDs in the output string. (The LIGATURES may contain strings of one code unit! This may lead to non-obvious behaviour! If pressing such a key after a deadkey generates a chained deadkey, this would happen without delivering WM_DEADKEY message.)

NOTE: How kernel recognizes which key sequences contribute to character-by-number input via numeric KeyPad? First, the starter keydown must happen when the ORed mask contains KBDALT, and no other bits except KBDSHIFT and KBDKANA. (E.g., one can press Alt, then tap f 1 2 3, release Alt [with 1,2,3 on the numeric keypad]. This would deliver Alt-f, then 1 would start character-by-number input provided Alt and NumPad1 together have ORed mask “in between” of KBDALT and KBDALT|KBDSHIFT|KBDKANA.)

After the starter keydown (NumPad: 0..9, DOT, PLUS) is recognized as such, all the keyups should be followed by the corresponding keydown (keydowns-due-to-repeat are ignored); more precisely, between two KEYDOWN events, the KEYUP for the first of them must be present. (In other words, KEYDOWN/KEYUP events must come in the expected order, maybe with some intermixed “extra” KEYUP events.) In the decimal mode (numeric starter) only the keys with scancodes of NumPad 0..9 are allowed. In the hex mode (starter is NumPad's DOT or PLUS) also the keys with virtual codes '0'..'9' and 'A'..'F' are allowed. The sequence is terminated by releasing VK_MENU (=Alt) key.

NOTE: In most cases, the resulting number is reduced mod 256. The exceptions are: the starter key is KeyPadPLUS, or the translate-to codepage is multibyte (and the number is interpreted as big-endian). In multibyte codepages, (reduced) numbers above 0x80 are considered in cp1252 codepage (unless the translate-to codepage is Japanese, and the number’s codepoint is Katakana).

NOTE: If the starter key is KeyPad0 or KeyPadDOT, the number is a codepoint in the default codepage of the keyboard layout; if it is another digit, it is in the OEM codepage. Hex mode (KeyPadPLUS or KeyPadDOT) requires extra tinkering; see "Hex input of unicode is not enabled".

NOTE: since keyboard layout normally map Alt to the mask KBDALT, and do not define a modification column for the ORed mask =KBDALT, and KBDALT is NOT stripped for key events in input-by-number, these key events usually do not generate spurious WM_CHARs.

Keyboard input on Windows, Part III: Customary “special” keybindings of typical keyboards

Typically, keyboards define a few keypresses which deliver “control” characters (for benefits of console applications). As shown above, even if the keyboard does not define Control-letter combinations (but does define modification column for Ctrl which is associated to KBDCTRL — with maybe KBDSHIFT, KBDKANA intermixed), WM_CHAR with ^letter will be delivered to the application. Same with happen for combinations with modifiers which produce only KBDCTRL, KBDSHIFT, KBDKANA.

Additionally, the typical keyboards also define the following bindings:

  Ctrl-Space     ——→ 0x20
  Esc, Ctrl-[    ——→ 0x1b
  Ctrl-]         ——→ 0x1d
  Ctrl-\         ——→ 0x1c
  BackSpace      ——→ ^H
  Ctrl-BackSpace ——→ 0x7f
  Ctrl-Break     ——→ ^C
  Tab            ——→ ^I
  Enter          ——→ ^M
  Ctrl-Enter     ——→ ^J

In addition to this, the standard US keyboard (and keyboards built by this module) define the following bindings with Ctrl-Shift modifiers:

  @      ——→ 0x00
  ^      ——→ 0x1e
  _      ——→ 0x1f

Can an application on Windows accept keyboard events? Part I: insert only

The logic described above makes the kernel deliver more or less “correct” WM_(SYS)CHAR messages to the application. The only bindings which may be defined in the keyboard, but will not be seen as WM_(SYS)CHAR are those in modification columns which involve KBDALT, and do not involve any bits except KBDSHIFT and KBDKANA. (Due to the stripping of KBDALT described above, these modification columns are never accessed — well, they are, but only for input-by-number.)

Try to design an application with an entry field; the application should insert ALL the characters ”delivered for insertion” by the keyboard layout and the kernel. The application should not do anything else for all the other keyboard events. First, ignore the KBDALT stripping.

Then the only WM_(SYS)CHAR which are NOT supposed to insert the contents to the editable UI fields are the "Customary “special” keybindings" described above. They are easy to recognize and ignore: just ignore all the WM_(SYS)CHAR carrying characters in the range 0x00..0x1f, 0x7f, and ignore 0x20 delivered when one of Ctrl keys is down. So the application which inserts all the other WM_(SYS)CHARs will follow the intent of the keyboard as close as possible.

Now return to consideration of KBDALT stripping. If the application follows the policy above, pressing Alt-b would enter b — provided Alt is mapped to KBDALT, as done on standard keyboards. So the application should recognize which WM_CHAR carrying b are actually due to stripping of KBDALT, and should not insert the delivered characters.

Here comes the major flaw of the Windows’ keyboard subsystem: the kernel translates SCANCODE —→ VK_CODE —→ ORED_MASK —→ MODIFICATION_COLUMN, then operates in terms of ORed masks and modification columns. The application can access only the first two levels of this translation; one cannot query the kernel for any information about the last two numbers. (Except for the API VkKeyScanEx(), but it is unclear how this API may help: it translates “in wrong direction” and covers only BMP.) Therefore, there is no bullet-proof way to recognize when WM_(SYS)CHAR arrived due to KBDALT stripping.

NOTE: of course, if only Shift/Alt/Ctrl keys are associated to non-0 ORed mask bitmaps, and they are associated to the “expected” KBDSHIFT/KBDALT/KBDCTRL bits, then the application would easily recognize this situation by checking whether Alt is down, but Ctrl is not. (Also observe that this is exactly the situation distinguishing WM_CHAR from WM_SYSCHAR — no surprises here!)

Assuming that the application uses this method, it would correctly recognize stripped events on the “primitive” keyboards. However, on a keyboard with an extra modifier key (call it Super; assume its mask to involve a non-SHIFT/ALT/CTRL/KANA bit), the Alt-Super-key combination will not be stripped by the kernel, but the application would think that it was, and would not insert the character in WM_CHAR message. A bug!

Moreover, if “supporing only the naive mapping” were a feasible restriction, there would be no reason for the kernel to go through the extra step of “the ORed mask”. Actually, to have a keyboard which is simultaneously backward compatible, easy for users, and covering a sufficiently wide range of possible characters, one must use more or less convoluted implementations (as in "A convenient assignment of KBD* bitmaps to modifier keys").

CONCLUSION: the fact that the kernel and the applications speak different incompatible languages makes even the primitive task discussed here impossible to code in a bullet-proof way. A heuristic workaround exists, but it will not work with all keyboards and all combinations of modifiers.

CAVEAT with the above assignment: some applications (e.g., Emacs) manage to distinguish lCtrl+lAlt combination of modifier keys from the combination lCtrl+rAlt produced by a typical AltGr; these applications are able to use lCtrl+lAlt-modified keys as a bindable accelerator keys. Currently, it is not clear how to embrace these applications into the above scheme, without giving up the lCtrl+lAlt-key combination as character-producing combinations.

Can an application on Windows accept keyboard events? Part II: special key events

In the preceding section, we considered the most primitive application accepting the user inserting of characters, and nothing more. “Real applications” must support also keyboard actions different from “insertion”; so those KEYDOWN events which are not related to insertion may trigger some “special actions”. To model a full-featured keyboard input, consider the following specification:

As above, the application has an entry field, and should insert ALL the characters ”delivered for insertion” by the keyboard layout and the kernel. For all the keyboard events not related to insertion of characters, the application should write to the log file which of Ctrl/Alt/Shift modifiers were down, and the virtual keycode of the KEYDOWN event. Again, at first, we ignore the KBDALT stripping.

At first, the problem looks simple: with the standard message pump, when WM_(SYS)KEYDOWN message is processed, the corresponding WM_(SYS)(DEAD)CHAR messages are already sent to the message queue. One can PeekMessage() for these messages; if present, and not “special”, they correspond to “insertion”, so nothing should be written to the log. Otherwise, one reports this WM_(SYS)KEYDOWN to the log.

Unfortunately, this solution is wrong. Inspect again what the kernel is delivering during the input-by-number via numeric keyboard: the KEYDOWN for decimal/hex digits is a part of the “insertion”, but it does not generate any WM_(SYS)(DEAD)CHAR. Essentially, the application may see Alt-F pressed during the processing of Alt-NumPadPlus+F+1+2, but even if Alt-F is supposed to format the paragraph, this action should not be triggered (but U+0F12 should be eventually inserted).

CONCLUSION: Input-by-number is getting in the way of using the standard message pump. SOLUTION: one should write a clone of TranslateMessage() which delivers suitable WM_USER* messages for KEYDOWN/KEYUP involved in Input-by-number. Doing this, one can also remove sillyness from the Windows’ handling of Input-by-number (such as taking mod 256 for numbers above 255).

POSSIBLE IMPLEMENTATION: myTranslateMessage() should:

Combining this with the heuristical recognition of stripped KBDALT, one gets an architecture with a naive approximation to handling of Alt (but still miles ahead of all the applications I saw!), and bullet-proof handling of other combinations of modifiers.

NOTE: this implementation of MyTranslateMessage() loses one “feature” of the original one: that input-by-number is disabled in the presence of (popup) menu. However, since I never saw this “feature” in action (and never have heard of it described anywhere), this must be of negligible price.

NOTE: ALL the applications I checked do this logic wrong. Most of them check FIRST for “whether the key event looks like those which should trigger special actions”, then perform these special actions (and ignore the character payload).

As shown above, the reasonable way is to do this in the opposite order, and check for special actions only AFTER it is known that the key event does not carry a character payload. The impossibility of reversing the order of these checks is due to the same reason as one discussed above: the kernel and application speaking different languages.

Indeed, since the application knows nothing about ORed masks, it has no way to distinguish that, for example, lCtrl-rCtrl-= may be SUPPOSED to be distinct from lCtrl-= and rCtrl-=, and while the last two do not carry the character payload, the first one does. Checking FIRST for the absense of WM_(SYS)(DEAD)CHAR delegates such a discrimination to the kernel, which has enough information about the intent of the keyboard layout. (Likewise, the keyboard may define the pair of DEADKEY and Ctrl-A to insert ᵃ. Then Ctrl-A alone will not carry any character payload, its combination with a deadkey may.)

Why the applications are trying to grab the potential special-key messages as early as possible? I suspect that the developers are afraid that otherwise, a keyboard layout may “steal” important accelerators from the application. While this is technically possible, nowadays keyboard accelerators are rarely the only way to access features of the applications; and among hundreds of keyboard layout I saw, all but 2 or 3 would not “steal” anything from applications. (Or maybe the developers just have no clue that the correct solution is so simple?)

NOTE: Among the applications I checked, the worst offender is Firefox. It follows a particularly unfortunate advice by Mike Kaplan and tries to reconstruct the mentioned above row/columns table of the keyboard layout, then uses this (heuristically reconstructed) table as a substitute for the real thing. And due to the mismatch of languages spoken by kernel and applications, working via such an attempted reconstruction turns out to have very little relationship to the actually intended behaviour of the keyboard (the behaviour observed in less baroque applications). In particular, if keyboards uses different modification columns for lCtrl-lAlt and AltGr=rAlt modifiers, pressing AltGr-key inputs wrong characters in Firefox.

NOTE: Among notable applications which fail spectacularly is Emacs. The developers forget that for a generation, it is already XXI century, and use ToAscii() instead of ToUnicode()! (Even if ToUnicode() is available, its result is converted to the result of the corresponding ToAscii() code.)

In addition to 8-bitness, Emacs also suffers from check-for-specials-first syndrome…

Can an application on Windows accept keyboard events? Part III: better detection of KBDALT stripping

We explained above that it is not possible to make a bullet-proof algorithm handling the case when KBDALT might have been stripped by the kernel. The very naive heuristic algorithm described there will recognize the simplest cases, but will also have many false positives: for many combinations it will decide that KBDALT was stripped while it was not. The result will be that when the kernel reports that the character X is delivered, the application would interpret it as Alt-X, so X would not be inserted. It will not handle, for example, the lAlt-Menu-key modifier combinations with the assignment of mask from that section.

Indeed, with this assignment, the only combination of modifiers for which the kernel will strip KBDALT is lAlt (and lAlt+Win if one does not assign anything any bits to Win). So lAlt-Menu-key is not stripped, hence the correct WM_*CHAR is delivered by the kernel. However, since this combination is still visible to the application as having Alt, and not having Ctrl, it is delivered as the SYS flavor.

So the net result is: one designed a nice assignment of masks to the modifier keys. This assignment makes keypresses successfully navigate around the quirks of the kernel’s calculations of the character to deliver. However, the naive algorithm used by the application will force the application to ignore this correctly delivered character to insert.

What one needs is an extra heuristic to recognize the combinations involving Alt and an “unexpected modifier”, so that these combinations become exceptions to the rule “SYS flavor means ‘do not insert’”.

SOLUTION: when WM_SYS*CHAR message arrives, inspect the virtual keycodes which are reported as pressed. Ignore the keycode for the current message. Ignore the keycodes for “usual modifiers” (Shift/Alt/Kana) which are expected to keep stripping. Ignore the keycode for the keys which may be kept “stuck down” by the keyboards (see "Far Eastern keyboards on Windows"). If some keycode remains, then consider it as an “extra” modifier, and ignore the fact that the message was of SYS flavor.

So all one must do is to define one user message, code two very simple routines, MyTranslateMessage() and HasExtraModifiersHeuristical(), and perform two PeekMessage() on KEYDOWN event, and one gets a powerful almost-robust algorithm for keyboard input on Windows. (Recall that all the applications I saw provide close-to-abysmal support of keyboard input on Windows.)

Far Eastern keyboards on Windows

The syntax of defining these keyboards is documented in kbd.h of the toolkit. The semantic is undocumented. Here we fix this.

In short, these layouts have an extra table which may define the following enhancements:

  One 3-state (or 2-state) radio-button:
         (the third state can be also toggled independently of the others).
  Three Toggling (like CAPSLOCK) button (pairs): 
  Make key produce different VK codes with different modifiers.
  Make a “reverse NUMPAD” translation.
  Manipulate a couple of bits of IME state.
  A few random hacks for key-deficient hardware layouts.

(One may use the usual maps to modification columns to make the radio-buttons and toggle-buttons above affect the layout. Using this, it is easy to convert each toggling buttons to 2-state radiobuttons. The limitation is that the number of modification columns compatible with the extra table is at most 8 — counting one for Ctrl.)

Every VK may be associated to two tables of functions, the “normal” one, and the “alternative” one. Both tables associate a keyboard-description-column to a filter id, and a parameter for the filter. (Recall that columns are associated to the 6-bit modifier state by the table in the MODIFIERS structure. One must define all the states reachable by the modifier keys. NOTE: the limit on the number of states in the tables is 8; it is not clear what happens with the states above this.)

The filters operate on: VK, UP/DOWN flag, the flags associated to the scancode in KBDTABLES->ausVK (may be added to upsteam), the parameter given in VK_F structure (and an unused DWORD read/write parameter). A filter may change these parameters, then pass the event forward, or it may ignore an event. Filters by ID:

  KBDNLS_NULL           Ignore key (should not be called; only for unreachable slots in the tables).
  KBDNLS_NOEVENT        Ignore key.
  KBDNLS_SEND_BASE_VK   Pass through VK unchanged.
  KBDNLS_SEND_PARAM_VK  Replace VK by the number specified as the parameter.
  KBDNLS_KANAMODE       Ignore UP; on DOWN, generate UP-or-DOWN for DBE_KATAKANA
  KBDNLS_ROMAN          Ignore UP;      Toggle DBE_ROMAN / DBE_NOROMAN
  KBDNLS_HELP_OR_END    Pass-through if NUMPAD flag ON (in ausVK); send-or-toggle HELP/END (see below)
  KBDNLS_HOME_OR_CLEAR  Pass-through if NUMPAD flag ON (in ausVK); send HOME/CLEAR (see below)
  KBDNLS_NUMPAD         If !NUMLOCK | SHIFT, replace NUMPADn/DECIMAL by no-numpad flavors
  KBDNLS_KANAEVENT      Replace VK by the number specified as the parameter. On DOWN, see below
  KBDNLS_CONV_OR_NONCONV        See below


Typical usages:

  KBDNLS_KANAMODE (VK_KANA (Special case))
  KBDNLS_NUMPAD (VK_xxx for Numpad)          [NEC PC-9800 Only]
  KBDNLS_KANAEVENT (VK_KANA) [Fujitsu FMV oyayubi Only] 

Toggle (= 2-state) and 3-state radio-keys are switched by sending KEYUP for the currently “active” key, then KEYDOWN for the newly activated key. When switching 3-state, additional action happens depending on the new state:

  DBE_ALPHANUMERIC      If IME is off, and KANA toggle is on,  switch IME on  in the KATAKANA mode
  DBE_HIRAGANA          If IME is off, and KANA toggle is off, switch IME off in the ALPHANUMERIC mode

Additionally, KEYDOWN of KBDNLS_KANAEVENT switches IME to

  KANA toggle on:               switch IME off in the ALPHANUMERIC mode
  KANA toggle off:              switch IME on  in the KATAKANA mode

and KBDNLS_CONV_OR_NONCONV (on KEYUP and KEYDOWN) passes through, and does

  KANA toggle on, IME off:      switch IME off in the ALPHANUMERIC mode
  otherwise:                    Do nothing

(The semantic of IME being-in/switching-to OFF/ON mode is not clear (probably IME-specific). The switching happens by calling RequestDeviceChange(pDeviceInfo, GDIAF_IME_STATUS, TRUE) for devices with a handle and type == DEVICE_TYPE_KEYBOARD, while putting the request at into global memory — unless IMECOMPAT_HYDRACLIENT flag is set on the foreground keyboard.)

For KBDNLS_HOME_OR_CLEAR, the registry is checked at statup. For KBDNLS_HELP_OR_END, the registry is checked at statup, and:

  KANA_AWARE:   flips END/HELP if KANA toggle is ON (on input, “HELP” means not-an-END)
  otherwise:    sends END/HELP depending on what registry says.

The checked values are helpkey, KanaHelpKey, clrkey in the hive RTL_REGISTRY_WINDOWS_NT\WOW\keyboard.

Which of two tables is chosen is controlled by the type (NULL/NORMAL/TOGGLE) of the key's tables, and the (per key) history bit. The initial state of the bit is in NLSFEProcCurrent (StuxNet hits here!). The tables of type NULL are ignored (the key descriptor passes all events through), the NORMAL key uses only the first table. The TOGGLE key uses the first table on KEYDOWN, and uses the first or the second table on KEYUP. The choice depends on modifiers present in the preceding KEYDOWN; the bitmap NLSFEProcSwitch is indexed by the modification column of KEYDOWN event; the second table is used on the following KEYUP if the indexed bit is set. (The KEYREPEAT events are handled the same way as KEYUP.)

The typical usage of TOGGLE keys is to make the KEYUP event match what KEYDOWN did no matter what is the order of releasing the modifier keys and the main key. Having this bit “propagates” to KEYUP the information about which modifiers were active on KEYDOWN. This helps in ensuring consistency of some actions between the KEYDOWN event and the corresponding KEYUP event: remember that the state of modifiers on KEYUP is often different than the state on KEYDOWN: people can release modifiers in different orders:

  press-Shift, press-Enter, release-Shift, release-Enter        --->    Shift-Enter pressed, Enter released
  press-Shift, press-Enter, release-Enter, release-Shift        --->    Shift-Enter pressed and released

If pressing Shift-Enter acts as if it were the F38 key (and only so with Shift!), to ensure consistency, one would need to make releasing Shift-Enter and also releasing Enter to act as if it were the F38 key. So one can make pressing Shift-Enter special (via the first table), sets the history bit on Shift-Enter, and make the second table map Enter and Shift-Enter to be special too (send F38) if the history bit is set.

Remark: the standard key processing has its own filters too. AltGr processing adds fake lCtrl up/down events; Shift-Cancels-CapsLock processing ignores/fakes the KEYDOWN/KEYUP for Capital; Shift-Multiply becomes VK_SNAPSHOT (same for Alt; Ctrl-ScrollLck/Numlock become VK_CANCEL/VK_PAUSE; Ctrl-Pause may become VK_CANCEL. OEM translations (NumPad→Cursor, except C-A-Del; 00 to double-press of 0) come first, then locale-specific (AltGr, Shift-Cancels-CapsLock), then those defined in the tables above.

Remark: As opposed to these translations, KLLF_LRM_RLM and Alt-NUMPADn) is actually handled inside the even loop, by ToUnicode().

Remark: (and references inside!) explains fine points of using Japanese keyboards. See also:

A convenient assignment of KBD* bitmaps to modifier keys

In this section, we omit discussion of Shift modifier; so every bitmap may be further combined with KBDSHIFT to produce two different bindings:

  lCtrl         Win      lAlt           rAlt                    Menu            rCtrl

with suitable backward-compatible mapping of ORed masks to modification columns. This assignment allows using KLLF_ALTGR flag (faking presses of lCtrl when rAlt is pressed — this greatly increases compatibility of rAlt with brain-damaged applications), all the combinations involving at most one of lCtrl, Win or rAlt give distinct ORed masks, it avoids stripping of KBDALT on lAlt combined with other modifiers, makes CapsLock work with all relevant combinations, while completely preserving all application-visible properties of keyboard events [except those with lCtrl-Win-lAlt- modifiers; this combination is equivalent to lAlt-rAlt-].

Note that ignoring the CTRL and ALT bits, all combinations of LOYA,KANA,X1,X2,ROYA are possible, which gives at least 32 Shift-pairs. In fact, the only combination of LOYA,KANA,X1,X2,ROYA which may appear with different CTRL,ALT bits is LOYA|X1; hence there are 33 possible combinations of CTRL,ALT,LOYA,KANA,X1,X2,ROYA. Indeed, CTRL is determined by LOYA|X1|X2|ROYA. If one of KANA,X2,ROYA is present, then ALT is set; so assume KANA,X2,ROYA are not present. But then, if ALT may be set, then both LOYA|X1 must be present; which gives the only duplication.

Leaving out 5 combinations of lCtrl, Win, lAlt [8, minus the empty one, and lCtrl+lAlt, which is avoided by most application due to its similarity to AltGr=rAlt, and lCtrl+Win+lAlt which is undistinguishable by the mask from lAlt+rAlt] to have bindable keypresses in applications, and having rCtrl as equivalent to lCtrl, this gives 27 Shift-pairs which may produce characters.

NOTE: lCtrl+Win+lAlt being undistinguishable by the mask from lAlt+rAlt is not a big deal, since there is no standard keyboard shortcuts involving Ctrl+Win+Alt.

NOTE: Combinations of lCtrl with rCtrl cause several problems.

NOTE: Removing the binding for Win key, only 21 useful Shift-pairs remain. (This is what version 0.63 of izKeys keyboard layout is using; out of 24 distinct combinations, lAlt, lCtrl and rCtrl should be excluded.) Trivia: While this may look as a complete overkill, recall that characters outside BMP can be inserted on Windows only via one keypress, possibly with many modifiers. (This restriction relates only to the “classical” flavor of Windows keyboard layouts). Unicode defines 18 additional Latin/Greek alphabets for mathematical discourse. If a keyboard layout would want to support these letters, this would quickly exhaust the possible combinations of modifiers. (For 2-script layout, one could live with Latin/AltGr-Latin/Greek + 18 mathematical alphabets. But for layouts supporting more scripts, it lookes like using Win key is not avoidable.)

NOTE: Applications may call ToUnicode() with impossible combinations of modifiers: for example, they may put Ctrl down, but do not specify whether it is rCtrl or lCtrl. Likewise for Alt.

To support that, one would need to define a mask for standalone VK_CONTROL and VK_MENU (i.e., Ctrl and Alt). Since these modifiers are present when the real “left-right-handed” keys are down, the masks should be “contained” in the masks of handed keys. Example: one can make the pseudo-key Ctrl to generate bit CTRL, and the pseudo-key Alt to generate the bit ALT. Then for any combination of modifiers with unhanded Ctrl and/or Alt, either the corresponding combination of bits is supported by the layout (and then the application will access the corresponding modification column — which is probably not the “expected” column corresponding to some handed flavor), or the combination is not yet defined. In the latter case, one may actually decide how to resolve this: one can map this combination of modifiers to an arbitatrary modification column!

In particular, one can map such combination of modifiers to a certain choice of handedness of Ctrl and Alt. (An example of such a problematic application is Firefox; look for “impossible modifier”.)


The keyboard(s) generated with this module: UI::KeyboardLayout::izKeys,

On diacritics:                 (Chars of languages)

     Accents in different Languages:,12,inne_diakrytyki.htm#07

On typography marks

On keyboard layouts:           (used almost nowhere - only half of keys in Canadian multilanguage match)
      Discussion of layout changes and position of €:
    History of QUERTY                     (Academic for Mac)                     (Old Irish mechanical typewriters)                    (One-handed layout)   (and references there)
      Images in (download of)
      Neo2 sources:
      Shift keys at center, nice graphic:
      Physical keyboard:
      Polytonic Greek
      Portable keyboard layout
      Typing on numeric keypad
      On screen keyboard indicator
      Keyboards of ЕС-1840/1/5
     (    Руководство пользователя ПЭВМ
      Phonetic Hebrew layout(s) (1st has many duplicates, 2nd overweighted)
      Greek (Galaxy) with a convenient mapping (except for Ψ) and BibleScript
      With 2-letter input of Unicode names:
      Yandex visual keyboards
      Implementation in FireFox
      Implementation in Emacs 24.3 (ToUnicode() in fns)
      Naive implementations:
      Quality of a keyboard

Manipulating keyboards on Windows and X11             (using links there: up to Win7)

MSKLC parser

By author of MSKLC Michael S. Kaplan (do not forget to follow links)

      Input on Windows:
      Chaining dead keys:
      Mapping VK to VSC etc:
      [Link] Remapping CapsLock to mean Backspace in a keyboard layout
            (if repeat, every second Press counts ;-)
      Scancodes from kbd.h get in the way
      What happens if you start with .klc with other VK_ mappings:
      Keyboards with Ctrl-Shift states:
      On assigning Ctrl-values
      On hotkeys for switching layouts:
      Text services
      Low-level access in MSKLC
      On font linking
      Unicode in console
      Adding formerly "invisible" keys to the keyboard
      Redefining NumKeypad keys
      And backspace/return/etc
       kbdutool.exe, run with the /S  ==> .c files
      Doing one's own WM_DEADKEY processing'
      Dead keys do not work on SG-Caps
      Dynamic keycaps keyboard
      Backslash/yen/won confusion
      Unicode output to console
      Install/Load/Activate an input method/layout
      Reset to a TT font from an application:
      How to (not) treat C-A-Q
      Treating Brazilian ABNT c1 c2 keys
      And JIS ¥|-key
         (compare with
      Suggest a topic:

Installable Keyboard Layouts - Apple Developer (“.keylayout” files; modifiers not editable; cache may create problems; to enable deadkeys in X11, one may need extra work)

Different ways to access chars on Mac (1ˢᵗ suggests adding a Discover via plists via Keycaps≠Strings)                  Default keybindings                  Mystery keys on Mac                                            Patching ADB drivers                              Patching USB drivers (gives LCtrl vs RCtrl etc???)                                (has no docs???)

Compose on Mac requires hacks:

Convert Apple to MSKLC

VK_OEM_8 Kana modifier - Using instead of AltGr Limitations of using KANA toggle

FE (Far Eastern) keyboard source code example (NEC AT is 106 with SPECIAL MULTIVK flags changed on some scancodes, OEM_7/8 producing 0x1e 0x1f, and no OEM_102):

        Investigation on relation between VK_ asignments, KBDEXT, KBDNUMPAD etc:

    PowerShell vs ISE (and how to find them [On Win7: WinKey Accessories]

  Google for "Get modification number for Shift key" for code to query the kbd DLL directly ("keylogger")

  How to read Unicode in an ANSI Window:

HTML consolidated entity names and discussion, MES charsets:


Low level scancode mapping
  the free remapkey.exe utility that's in Microsoft NT / 2000 resource kit.

  perl -wlne "BEGIN{$t = {T => q(), qw( X e0 Y e1 )}} print qq(  $t->{$1}$2\t$3) if /^#define\s+([TXY])([0-9a-f]{2})\s+(?:_EQ|_NE)\((?:(?:\s*\w+\s*,){3})?\s*([^\W_]\w*)\s*(?:(?:,\s*\w+\s*){2})?\)\s*(?:\/\/.*)?$/i" kbd.h >ll2
    then select stuff up to the first e1 key (but DECIMAL is not there T53 is DELETE??? take from MSKLC help/using/advanced/scancodes)

CapsLock as on typewriter:

Problems on X11:                   (definition of XKB???)                     (current???)                       (current???)        (current???)                  (documents almost 1/2 of the needed stuff)                                        (2005++ ???)    (2009++ HAS: How to make CapsLock change layouts)                                (of 2008???)                                     (of 2005???)                           (of 1999???)


  ./xkb in /etc/X11 /usr/local/X11 /usr/share/local/X11 /usr/share/X11
    (maybe it is more productive to try
      ls -d /*/*/xkb  /*/*/*/xkb
  but what dead_diaresis means is defined here:
     Apparently, may be in /usr/X11R6/lib/X11/locale/en_US.UTF-8/Compose /usr/share/X11/locale/en_US.UTF-8/Compose

Note: have XIM input method in GTK disables Control-Shift-u way of entering HEX unicode.

    How to contribute:

Note: the problems with handling deadkeys via .Compose are that: .Compose is handled by applications, while keymaps by server (since they may be on different machines, things can easily get out of sync); .Compose knows nothing about the current "Keyboard group" or of the state of CapsLock etc (therefore emulating "group switch" via composing is impossible).

JS code to add "insert these chars": google for editpage_specialchars_cyrilic, or

Latin paleography       (Uncomplete???)        (No prioritization...)

Summary tables for Cyrillic                 - per language tables

     Extra chars (see also the ordering table on page 8)
     Typesetting Old and Modern Church Slavonic

     Non-dialogue of Slavists and Unicode experts
     Newer: (+ combining ф)            As below, plus N-left-hook, ДЗЖ ДЧ, L-descender, modifier-Ь/Ъ             (5 VS for Mark's chapter, 2 VS for t, 1 VS for the rest)       typikon (+[semi]circled), ε-form       inverted ε-typikon       two variants of o/O       Mark's chapter       Reversed tse

    Table with Unicode points marked:
                        (except for "Lateral flap" and "Epiglottal" column/row.
    (Extended) IPA explained by consortium:
    IPA keyboard

Is this discussing KBDNLS_TYPE_TOGGLE on VK_KANA???

Windows: fonts substitution/fallback/replacement

Problems on Windows:

    Console font: Lucida Console 14 is viewable, but has practically no Unicode support.
                  Consolas (good at 16) has much better Unicode support (sometimes better sometimes worse than DejaVue)
                  Dejavue is good at 14 (equal to a GUI font size 9 on 15in 1300px screen; 16px unifont is native at 12 here)
    Apparently, Windows picks up the flavor (Bold/Italic/Etc) of DejaVue at random; see
        - he got it in bold.  I''m getting it in italic...  Workaround: uninstall 
          all flavors but one (the BOOK flavor), THEN enable it for the console...  Then reinstall
          (preferably newer versions).

Display (how WikiPedia does it):
    In CSS:  .IPA, .Unicode { font-family: "Arial Unicode MS", "Lucida Sans Unicode"; }

Inspect which font is used by Firefox:

Windows shortcuts:

On meaning of Unicode math codepoints

Monospaced fonts with combining marks (!)

Indic ISCII - any hope with it? (This is not representable...:)

(Percieved) problems of Unicode (2001)

On a need to have input methods for unicode

On info on Unicode chars 

Zapf dingbats encoding, and other fine points of AdobeGL:

Yet another (IMO, silly) way to handle '; fight: ' vs ` ´

Surrogate characters on IE

  HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\International\Scripts\42                         Script IDs

Quoting tchrist: You can snag unichars, uniprops, and uninames from if you like.

Tom's unicode scripts

.XCompose: on docs and examples

Syntax of .XCompose is (partially) documented in

 #   Modifiers are not documented
 #       (Shift, Alt, Lock, Ctrl with aliases Meta, Caps; apparently,
 #               ! is applied to a sequence without ~ ???) 

Semantic (e.g., which of keybindings has a preference) is not documented. Experiments (see below) show that a longer binding wins; if same length, one which is loaded later wins. Relation with presence of modifiers is not clear.

 #      (the source of imLcPrs.c shows that the explansion of the
 #      shorter sequence is stored too - but the presence of
 #      ->succession means that the code to process the resulting
 #      tree ignores the expansion).

Before the syntax was documented: For the best approximation, read the parser's code, e.g., google for

    inurl:compose.c XCompose "XCompose" "XCompose" filetype:c

The actual use of the compiled compose table:

Apparently, the first node (= defined last) in the tree which matches keysym and modifiers is chosen. So to override <Foo> <Bar>, looks like (checked to work!) ~Ctrl <Foo> may be used... On the other hand, defining both <Foo> <Bar> <Baz> and (later) <Foo> ~Ctrl <Bar>, one would expect that <Foo> <Ctrl-Bar> <Baz> should still trigger the expansion of <Foo> <Bar> <Baz> — but it does not... See also:

The file .XCompose is processed by X11 clients on startup. The changes to this file should be seen immediately by all newly started clients (but GTK or QT applications may need extra config - see below) unless the directory ~/.compose-cache is present and has a cache file compatible with binary architecture (then until cache expires - one day after creation - changes are not seen). The name .XCompose may be overriden by environment variable XCOMPOSEFILE.

To get (better?) examples, google for "multi_key" partial alpha "DOUBLE-STRUCK".

  # include these first, so they may be overriden later
  include "%H/my-Compose/.XCompose-kragen"
  include "%H/my-Compose/.XCompose-ootync"
  include "%H/my-Compose/.XCompose-pSub"

Check success: kragen: \ space --> ␣; ootync: o F --> ℉; pSub: 0 0 --> ∞ ...

Older versions of X11 do not understand %L %S. - but understand %H

E.g. Debian Squeeze 6.0.6; according to

it has v 1:7.5+8+squeeze1).

   include "/etc/X11/locale/en_US.UTF-8/Compose"
   include "/usr/share/X11/locale/en_US.UTF-8/Compose"

Import default rules from the system Compose file: usually as above (but supported only on newer systems):

   include "%L"

detect the success of the lines above: get # by doing Compose + + ...

The next file to include have been generated by

  perl -wlne 'next if /#\s+CIRCLED/; print if />\s+<.*>\s+<.*>\s+<.*/' /usr/share/X11/locale/en_US.UTF-8/Compose
  ### Std tables contain quadruple prefix for GREEK VOWELS and CIRCLED stuff
  ### only.  But there is a lot of triple prefix...  
  perl -wne 'next if /#\s+CIRCLED/; $s{$1}++ or print qq( $1) if />\s+<.*>\s+<.*>\s+<.*"(.*)"/' /usr/share/X11/locale/en_US.UTF-8/Compose
  ##  – — ☭ ª º Ǖ ǖ Ǘ ǘ Ǚ ǚ Ǜ ǜ Ǟ ǟ Ǡ ǡ Ǭ ǭ Ǻ ǻ Ǿ ǿ Ȫ ȫ Ȭ ȭ Ȱ ȱ ʰ ʱ ʲ ʳ ʴ ʵ ʶ ʷ ʸ ˠ ˡ ˢ ˣ ˤ ΐ ΰ Ḉ ḉ Ḕ ḕ Ḗ ḗ Ḝ ḝ Ḯ ḯ Ḹ ḹ Ṍ ṍ Ṏ ṏ Ṑ ṑ Ṓ ṓ Ṝ ṝ Ṥ ṥ Ṧ ṧ Ṩ ṩ Ṹ ṹ Ṻ ṻ Ấ ấ Ầ ầ Ẩ ẩ Ẫ ẫ Ậ ậ Ắ ắ Ằ ằ Ẳ ẳ Ẵ ẵ Ặ ặ Ế ế Ề ề Ể ể Ễ ễ Ệ ệ Ố ố Ồ ồ Ổ ổ Ỗ ỗ Ộ ộ Ớ ớ Ờ ờ Ở ở Ỡ ỡ Ợ ợ Ứ ứ Ừ ừ Ử ử Ữ ữ Ự ự ἂ ἃ ἄ ἅ ἆ ἇ Ἂ Ἃ Ἄ Ἅ Ἆ Ἇ ἒ ἓ ἔ ἕ Ἒ Ἓ Ἔ Ἕ ἢ ἣ ἤ ἥ ἦ ἧ Ἢ Ἣ Ἤ Ἥ Ἦ Ἧ ἲ ἳ ἴ ἵ ἶ ἷ Ἲ Ἳ Ἴ Ἵ Ἶ Ἷ ὂ ὃ ὄ ὅ Ὂ Ὃ Ὄ Ὅ ὒ ὓ ὔ ὕ ὖ ὗ Ὓ Ὕ Ὗ ὢ ὣ ὤ ὥ ὦ ὧ Ὢ Ὣ Ὤ Ὥ Ὦ Ὧ ᾀ ᾁ ᾂ ᾃ ᾄ ᾅ ᾆ ᾇ ᾈ ᾉ ᾊ ᾋ ᾌ ᾍ ᾎ ᾏ ᾐ ᾑ ᾒ ᾓ ᾔ ᾕ ᾖ ᾗ ᾘ ᾙ ᾚ ᾛ ᾜ ᾝ ᾞ ᾟ ᾠ ᾡ ᾢ ᾣ ᾤ ᾥ ᾦ ᾧ ᾨ ᾩ ᾪ ᾫ ᾬ ᾭ ᾮ ᾯ ᾲ ᾴ ᾷ ῂ ῄ ῇ ῒ ῗ ῢ ῧ ῲ ῴ ῷ ⁱ ⁿ ℠ ™ שּׁ שּׂ а̏ А̏ е̏ Е̏ и̏ И̏ о̏ О̏ у̏ У̏ р̏ Р̏ 🙌

The folloing exerpt from NEO compose tables may be good if you use keyboards which do not generate dead keys, but may generate Cyrillic keys; in other situations, edit filtering/naming on the following download command and on the include line below. (For my taste, most bindings are useless since they contain keysymbols which may be generated with NEO, but not with less intimidating keylayouts.)

(Filtering may be important, since having a large file may significantly slow down client's startup (without ~/.compose-cache???).)

  # perl -wle 'foreach (qw(base cyrillic greek lang math)) {my @i=@ARGV; $i[-1] .= qq($_.module?format=txt); system @i}' wget -O - | perl -wlne 'print unless /<(U[\dA-F]{4,6}>|dead_|Greek_)/' >  .XCompose-neo-no-Udigits-no-dead-no-Greek
  include "%H/.XCompose-neo-no-Udigits-no-dead-no-Greek"
  # detect the success of the line above: get ♫ by doing Compose Compose (but this binding is overwritten later!)

  ###################################### Neo's Math contains junk at line 312

Print with something like (loading in a web browser after this):

  perl -l examples/filter-XCompose ~/.XCompose-neo-no-Udigits-no-dead-no-Greek > ! o-neo
  env LC_ALL=C sort -f o-neo | column -x -c 130 > ! /tmp/oo-neo-x

“Systematic” parts of rules in a few .XCompose

        ================== .XCompose    b=bepo          o=ootync        k=kragen        p=pSub  s=std
        b       Double-Struck           b
        o       circled ops             b
        O       big circled ops         b
        r       rotated                 b       8ACETUv  ∞

        -       sub                     p
        =       double arrows           po
        g       greek                   po
        m       math                    p       |=Double-Struck         rest haphasard...
        O       circles                 p       Oo
        S       stars                   p       Ss
        ^       sup                     p       added: i -
        |       daggers                 p

        Double  mathop                  ok      +*&|%8CNPQRZ AE

        #       thick-black arrows      o
        -,Num-  arrows                  o
        N/N     fractions               o
        hH      pointing hands          o
        O       circled ops             o
        o       degree                  o
        rR      roman nums              o
        \ UP    upper modifiers         o
        \ DN    lower modifiers         o
        {       set theoretic           o
        |       arrows |-->flavors      o
        UP /    roots                   o
        LFT DN  6-quotes, bold delim    o
        RT DN   9-quotes, bold delim    o
        UP,DN   super,sub               o

        DOUBLE-separated-by-&   op      k        ( ) 
        in-()   circled                 k       xx for tensor
        in-[]   boxed, dice, play-cards k
        BKSP after      revert          k
        < after         revert          k
        ` after         small-caps      k
        ' after         hook            k
        , after         hook below      k
        h after         phonetic        k

        #       musical                 k
        %0      ROMAN                   k       %_0 for two-digit
        %       roman                   k       %_  for two-digit
        *       stars                   k
        *.      var-greek               k
        *       greek                   k
        ++, 3   triple                  k
        +       double                  k
        ,       quotes                  k
        !, /    negate                  k
        6,9     6,9-quotes              k
        N N     fractions               k
        =       double-arrows, RET      k
        CMP x2  long names              k
        f       hand, pencils           k
        \       combining???            k
        ^       super, up modifier      k
        _       low modifiers           k
        |B, |W  chess, checkers, B&W    k
        |       double-struck           k
        ARROWS  ARROWS                  k

        !       dot below               s
        "       diaeresis               s
        '       acute                   s
        trail < left delimiter          s
        trail > right delimiter         s
        trail \ slopped variant         s
        ( ... ) circled                 s
        (       greek aspirations       s
        )       greek aspirations       s
        +       horn                    s
        ,       cedilla                 s
        .       dot above               s
        -       hor. bar                s
        /       diag, vert hor. bar     s
        ;       ogonek                  s
        =       double          s
        trail = double          s
        ?       hook above              s
        b       breve                   s
        c       check above             s
        iota    iota below              s
        trail 0338      negated         s
        o       ring above              s
        U       breve                   s
                        SOME HEBREW
        ^       circumblex              s
        ^ _     superscript             s
        ^ undbr superscript             s
        _       bar                     s
        _       subscript               s
        underbr subscript               s
        `       grave                   s
        ~       greek dieresis          s
        ~       tilde                   s
        overbar bar                     s
        ´       acute                   s       ´ is not '
        ¸       cedilla                 s       ¸ is cedilla


Currently only output for Windows keyboard layout drivers (via MSKLC) is available.

Currently only the keyboards with US-mapping of hardware keys to "the etched symbols" are supported (think of German physical keyboards where Y/Z keycaps are swapped: Z is etched between T and U, and Y is to the left of X, or French which swaps A and Q, or French or Russian physical keyboards which have more alphabetical keys than 26).

While the architecture of assembling a keyboard of small easy-to-describe pieces is (IMO) elegant and very powerful, and is proven to be useful, it still looks like a collection of independent hacks. Many of these hacks look quite similar; it would be great to find a way to unify them, so reduce the repertoir of operations for assembly.

The current documentation is a hodge-podge of semi-coherent rambling.

The implementation of the module is crumbling under its weight. Its evolution was by bloating (even when some design features were simplified). Since initially I had very little clue to which level of abstraction and flexibility the keyboard description would evolve, bloating accumulated to incredible amounts.


The position of Unicode consortium is, apparently, that the “name” of a Unicode character is “just an identifier”. In other words, its (primary) function is to identify a character uniquely: different characters should have different names, and that's it. Any other function is secondary, and “if it works, fine”; if it does not work, tough luck. If the name does not match how people use the character (and with the giant pool of defined characters, this has happened a few times), this is not a reason to abandon the name.

This position makes the practice of maintaining backward compatibility easy. There is documentation of obvious errors in the naming.

However, this module tries to extract a certain amount of orthogonality from the giant heap of characters defined in Unicode; the principal concept is “a mutator”. Most mutators are defined by programmatic inspection of names of characters and relations between names of different characters. (In other words, we base such mutators on names, not glyphs.) Here we sketch the irregularities uncovered during this process.

APL symbols with UP TACK and DOWN TACK look reverted w.r.t. other UP TACK and DOWN TACK symbols.

LESS-THAN, FULL MOON, GREATER-THAN, EQUALS GREEK RHO, MALE are defined with SYMBOL or SIGN at end, but (may) drop it when combined with modifiers via WITH. Likewise for SUBSET OF, SUPERSET OF, CONTAINS AS MEMBER, PARALLEL TO, EQUIVALENT TO, IDENTICAL TO.

Sometimes opposite happens, and SIGN appears out of blue sky; compare:


ENG is a combination of n with HOOK, but it is not marked as such in its name.

Sometimes a name of diacritic (after WITH) acquires an ACCENT at end (see U+0476).

Oftentimes the part to the left of WITH is not resolvable: sometimes it is underspecified (e.g, just TRIANGLE), sometimes it is overspecified (e.g., in LEFT VERTICAL BAR WITH QUILL), sometime it should be understood as a glyph-of-written-word (e.g, in END WITH LEFTWARDS ARROW ABOVE). Sometimes it just does not exist (e.g., LATIN LETTER REVERSED GLOTTAL STOP WITH STROKE - there is LATIN LETTER INVERTED GLOTTAL STOP, but not the reversed variant). Sometimes it is a defined synonym (VERTICAL BAR).

Sometimes it has something appended (N-ARY UNION OPERATOR WITH DOT).

Sometimes WITH is just a clarification (RIGHTWARDS HARPOON WITH BARB DOWNWARDS).

  1     AND
  1     ANTENNA
  1     BACK
  1     BLACK SUN
  1     BRIDE
  1     COUPLE
  1     END
  1     FISH CAKE
  1     GLOBE
  1     HEAVY OVAL
  1     HELMET
  1     MONEY
  1     NIGHT
  1     ON
  1     OR
  1     PAGE
  1     SMALL VEE
  1     SOON
  1     SQUARED UP
  1     TOP
  1     WHITE SUN
  2     HEART
  2     LEFT ARROW
  2     PARALLEL
  2     TIMES
  3     CHART
  3     CONTAINS
  3     TRIANGLE
  4     BANKNOTE
  4     DIAMOND
  4     PERSON
  11    CIRCLE
  11    FACE
  15    SQUARE

  perl -wlane "next unless /^Unresolved: <(.*?)>/; $s{$1}++; END{print qq($s{$_}\t$_) for keys %s}" oxx-us2 | sort -n > oxx-us2-sorted-kw

SQUARE WITH specify fill - not combining. FACE is not combining, same for HARPOONs.

Only CIRCLE WITH HORIZONTAL BAR is combining. Triangle is combining only with underbar and dot above.


Another way of compositing is OVER (but not UNDER!) and FROM BAR. See also ABOVE, BELOW - but only BELOW LONG DASH. Avoid WITH/AND after these.


HEART means WHITE HEART SUIT. TRIPLE HORIZONTAL BAR looks genuinely missing...

SEMIDIRECT PRODUCT means one of two, left or right???

This better be convertible by rounding/sharpening mutators, but see BUT NOT/WITH NOT/OR NOT/AND SINGLE LINE NOT/ABOVE SINGLE LINE NOT/ABOVE NOT

  2268    LESS-THAN BUT NOT EQUAL TO;             1.1
  2269    GREATER-THAN BUT NOT EQUAL TO;          1.1
  228A    SUBSET OF WITH NOT EQUAL TO;            1.1
  228B    SUPERSET OF WITH NOT EQUAL TO;          1.1
  @               Relations
  22E4    SQUARE IMAGE OF OR NOT EQUAL TO;                1.1
  22E5    SQUARE ORIGINAL OF OR NOT EQUAL TO;             1.1
  @@      2A00    Supplemental Mathematical Operators     2AFF
  @               Relational operators
          x (less-than but not equal to - 2268)
          x (greater-than but not equal to - 2269)
  2AB5    PRECEDES ABOVE NOT EQUAL TO;            3.2
  2AB6    SUCCEEDS ABOVE NOT EQUAL TO;            3.2
  @               Subset and superset relations
  2ACB    SUBSET OF ABOVE NOT EQUAL TO;           3.2

Looking into v6.1 reference PDFs, 2268,2269,2ab5,2ab6,2acb,2acc have two horizontal bars, 228A,228B,22e4,22e5,2a87,2a88,2ab1,2ab2 have one horizontal bar, Hence BUT NOT EQUAL TO and ABOVE NOT EQUAL TO are equivalent; so are WITH NOT EQUAL TO, OR NOT EQUAL TO, AND SINGLE-LINE NOT EQUAL TO and ABOVE SINGLE-LINE NOT EQUAL TO. (Square variants come only with one horizontal line?)

Set $ENV{UI_KEYBOARDLAYOUT_UNRESOLVED} to enable warnings. Then do

  perl -wlane "next unless /^Unresolved: <(.*?)>/; $s{$1}++; END{print qq($s{$_}\t$_) for keys %s}" oxx | sort -n > oxx-sorted-kw


Copyright (c) 2011-2013 Ilya Zakharevich <>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.0 or, at your option, any later version of Perl 5 you may have available.

The distributed examples may have their own copyrights.



Multiple linked faces (accessible as described in ChangeLog); designated Primary- and Secondary- switch keys (as Shift-Space and AltGr-Space now).

Soft hyphen as a deadkey may be not a good idea: following it by a special key (such as Shift-Tab, or Control-Enter) may insert the deadkey character??? Hence the character should be highly visible... (Now the key is invisible, so this is irrelevant...)

Currently linked layers must have exactly the same number of keys in VK-tables.

VK tables for TAB, BACK were BS. Same (remains) for the rest of unusual keys... (See TAB-was.) But UTOOL cannot handle them anyway...

Define an extra element in VK keys: linkable. Should be sorted first in the kbd map, and there should be the same number in linked lists. Non-linkable keys should not be linked together by deadkey access...

Interaction of FromToFlipShift with SelectRX not intuitive. This works: Diacritic[<sub>](SelectRX[[0-9]](FlipShift(Latin)))

DefinedTo cannot be put on Cyrillic 3a9 (yo to superscript disappears - due to duplication???).

... so we do it differently now, but: LinkLayer was not aggressively resolving all the occurences of a character on a layer before we started to combine it with Diacritic_if_undef... - and Cyrillic 3a9 is not helped...

via_parent() is broken - cannot replace for Diacritic_if_undef.

Currently, we map ephigraphic letters to capital letters - is it intuitive???

dotted circle ◌ 25CC

DeadKey_Map200A= FlipLayers #DeadKey_Map200A_0= Id(Russian-AltGr) #DeadKey_Map200A_1= Id(Russian) performs differently from the commented variant: it adds links to auto-filled keys...

Why ¨ on THIN SPACE inserts OGONEK after making ¨ multifaceted???

When splitting a name on OVER/BELOW/ABOVE, we need both sides as modifiers???

Ỳ currently unreachable (appears only in Latin-8 Celtic, is not on Wikipedia)

Somebody is putting an extra element at the end of arrays for layers??? - Probably SPACE...

Need to treat upside-down as a pseudo-decomposition.

We decompose reversed-smallcaps in one step - probably better add yet another two-steps variant...

When creating a <pseudo-stuff> treat SYMBOL/SIGN/FINAL FORM/ISOLATED FORM/INITIAL FORM/MEDIAL FORM; note that SIGN may be stripped: LESS-THAN SIGN becomes LESS-THAN WITH DOT

We do not do canonical-merging of diacritics; so one needs to specify VARIA in addition to GRAVE ACCENT.

We use a smartish algorithm to assign multiple diacritics to the same deadkey. A REALLY smart algorithm would use information about when a particular precombined form was introduced in Unicode...

Inspector tool for NamesList.txt:


AltGrMap should be made CapsLock aware (impossible: smart capslock works only on the first layer, so the dead char must be on the first layer). [May work for Shift-Space - but it has a bag of problems...]

Alas, CapsLock'ing a composition cannot be made stepwise. Hence one must calculate it directly. (Oups, Windows CapsLock is not configurable on AltGr-layer. One may need to convert it to VK_KANA???)

WarnConflicts[exceptions] and NoConflicts translation map parsing rules.

Need a way to map to a different face, not a different layer.

Vietnamese: to put second accent over ă, ơ (o/horn), put them over ae/oe; - including another ˘ which would "cancel the implied one", so will get o-horn itself. - Except for acute accent which should replaced by ¨, and hook must be replaced by ˆ. (Over ae/oe there is only macron and diaeresis over ae.)

Or: for the purpose of taking a second accent, AltGr-A behaves as Ă (or Â?), AltGr-O behaves as Ô (or O-horn Ơ?). Then Å and O/ behave as the other one... And ˚ puts the dot *below*, macron puts a hook. Exception: ¨ acts as ´ on the unaltered AE.

  While Å takes acute accent, one can always input it via putting ˚ on Á.

If Ê is on the keyboard (and macron puts a hook), then the only problem is how to enter a hook alone (double circumflex is not precombined), dot below (???), and accents on u-horn ư.

Mogrification rules for double accents: AE Å OE O/ Ù mogrify into hatted/horned versions; macron mogrifies into a hook; second hat modifies a hat into a horn. The only problem: one won't be able to enter double grave on U - use the OTHER combination of ¨ and `... And how to enter dot below on non-accented aue? Put ¨ on umlaut? What about Ë?

To allow . or , on VK_DECIMAL: maybe make CapsLock-dependent?

How to write this diacritic recipe: insert hacheck on AltGr-variant, but only if the breve on the base layer variant does not insert hacheck (so inserts breve)???

Sorting diacritics by usefulness: we want to apply one of accents from the given list to a given key (with l layers of 2 shift states). For each accent, we have 2l possible variants for composition; assign to 2 variants differing by Shift the minimum penalty of the two. For each layer we get several possible combinations of different priority; and for each layer, we have a certain number of slots open. We can redistribute combinations from the primary layer to secondary one, but not between secondary layers.

Work with slots one-by-one (so that the assignent is "monotinic" when the number of slots increases). Let m be the number of layers where slots are present. Take highest priority combinations; if the number of "extra" combinations in the primary layer is at least m, distribute the first m of them to secondary layers. If n<m of them are present, fill k layers which have no their own combinations first, then other n-k layers. More precisely, if n<=k, use the first n of "free" layers; if n>k, fill all free layers, then the last n-k of non-free layers.

Repeat as needed (on each step, at most one slot in each layer appears).

But we do not need to separate case-differing keys! How to fix?

All done, but this works only on the current face! To fix, need to pass to the translator all the face-characters present on the given key simultaneously.

  ===== Accent-key TAB accesses extra bindinges (including NUM->numbered one)
        (may be problematic with some applications???
         -- so duplicate it on + and @ if they is not occupied
         -- there is nothing related to AT in Unicode)

Diacritics_0218_0b56_0c34= May create such a thing... (0b56_0c34 invisible to the user).

  Hmm - how to combine penaltized keys with reversion?  It looks like
  the higher priority bindings would occupy the hottest slots in both
  direct and reverse bindings...

  Maybe additional forms Diacrtitics2S_* and Diacrtitics2E_* which fight
  for symbols of the same penalty from start and from end (with S winning
  on stuff exactly in the middle...).  (The E-form would also strip the last |-group.)

' Shift-Space (from US face) should access the second level of Russian face. To avoid infinite cycles, face-switch keys to non-private faces should be marked in each face...

"Acute makes sharper" is applicable to () too to get <>-parens...


When recognizing symbols for GREEK, treat LUNATE (as NOP). Try adding HEBREW LETTER at start as well...

Compare with: 8 basic accents: (English 78)

When a diacritic on a base letter expands to several variants, use them all (with penalty according to the flags).

Problem: acute on acute makes double acute modifier...

Penalized letter are temporarily completely ignored; need to attach them in the end... - but not 02dd which should be completely ignore...

Report characters available on diacritic chains, but not accessible via such chains. Likewise for characters not accessible at all. Mark certain chains as "Hacks" so that they are not counted in these lists.

Long s and "preceded by" are not handled since the table has its own (useless) compatibility decompositions.

    On top of a light-lines grid (3×2, 2×3, 2×2; H, V, V+H):
 ╼†━†╾†╺†╸†╶†─†╴†╌†┄†┈† †╍†┅†┉†
 ╼━╾╺╸╶─╴╌┄┈ ╍┅┉

 ╲ ╱
 ▌ ▐



First of all, keyboard layouts on Windows are controlled by DLLs; the only function of these DLLs is to export a table of "actions" to perform. This table is passed to the kernel, and that's it - whatever is not supported by the format of this table cannot be implemented by native layouts. (The DLL performs no "actions" when actual keyboard events arrive.)

Essentially, the logic is like that: there are primary "keypresses", and chained "keypresses" ("prefix keys" [= deadkeys] and keys pressed after them). Primary keypresses are distinguished by which physical key on keyboard is pressed, and which of "modifier keys" are also pressed at this moment (as well as the state of "latched keys" - usually CapsLock only, but may be also Kana). This combination determines which Unicode character is generated by the keypress, and whether this character starts a "chained sequence".

On the other hand, the behaviour of chained keys is governed ONLY by Unicode characters they generate: if there are several physical keypresses generating the same Unicode characters, these keypresses are completely interchangeable inside a chained sequence. (The only restriction is that the first keypress should be marked as "prefix key"; for example, there may be two keys producing - so that one is producing a "real dash sign", and another is producing a "prefix" -.)

The table allows: to map ScanCodes to VK_keys; to associate a VK_key to several (numbered) choices of characters to output, and mark some of these choices as prefixes (deadkeys). (These "base" choices may contain up to 4 16-bit characters (with 32-bit characters mapped to 2 16-bit surrogates); but only those with 1 16-bit character may be marked as deadkeys.) For each prefix character (not a prefix key!) one can associate a table mapping input 16-bit "base characters" to output 16-bit characters, and mark some of the output choices as prefix characters.

The numbered choices above are determined by the state of "modifier keys" (such as Shift, Alt, Control), but not directly. First of all, VK_keys may be associated to a certain combination of 6 "modifier bits" (called "logical" Shift, Alt, Control, Kana, User1 and User2, but the logical bits are not required to coincide with names of modifier keys). (Example: one can bind Right Control to activate Shift and Kana bits.) The 64 possible combinations of modifier bits are mapped to the numbered choices above.

Additionally, one can define two "separate numbered choices" in presence of CapsLock (but the only allowed modifier bit is Shift). The another way to determine what CapsLock is doing: one can mark that it flips the "logical Shift" bit (separately on no-modifiers state, Control-Alt-only state, and Kana-only state [?!] - here "only" allow for the Shift bit to be ON).

AltGr key is considered equivalent to Control-Alt combination (of those are present, or always???), and one cannot bind Alt and Alt-Shift combinations. Additionally, binding bare Control modifier on alphabetical keys (and SPACE, [, ], \) may confuse some applications.

NOTE: there is some additional stuff allowed to be done (but only in presence of Far_East_Support installed???). FE-keyboards can define some sticky state (so may define some other "latching" keys in addition to CapsLock). However, I did not find a clear documentation yet (keyboard106 in the DDK toolkit???).

There is a tool to create/compile the required DLL: kbdutool.exe of MicroSoft Keyboard Layout Creator (with a graphic frontend MSKLC.exe). The tool does not support customization of modifier bits, and has numerous bugs concerning binding keys which usually do not generate characters. The graphic frontend does not support chained prefix keys, adds another batch of bugs, and has arbitrarily limitations: refuses to work if the compiled version of keyboard is already installed; refuses to work if SPACE is redefined in useful ways.

WORKFLOW: uninstall the keyboard, comment the definition of SPACE, load in MSKLC and create an install package. Then uncomment the definition of SPACE, and compile 4 architecture versions using kbdutool, moving the DLLs into suitable directories of the install package. Install the keyboard.

For development cycle, one does not need to rebuild the install package while recompiling.

The following sections classify GOTCHAS into 3 categories:

"WINDOWS GOTCHAS for keyboard users"

"WINDOWS GOTCHAS for keyboard developers using MSKLC"

"WINDOWS GOTCHAS for keyboard developers (problems in kernel)"

WINDOWS GOTCHAS for keyboard users ^

MSKLC keyboards not working on Windows 8 without reboot

The layout is shown as active, but "preview" is grayed out, and is not shown on the Win-Space list. See also:

The workaround is to reboot. Compare with

Default keyboard of an application

Apparently, there is no way to choose a default keyboard for a certain language. The configuration UI allows moving keyboards up and down in the list, but, apparently, this order is not related to which keyboard is selected when an application starts. (This may be fixed on Windows 8?)

Hex input of unicode is not enabled

One needs to explicitly tinker with the registry (see examples/enable-hex-unicode-entry.reg) and then reboot to enable this.

Standard fonts have some chars exchanged

At least in Consolas and Lucida Sans Unicode φ and ϕ are exchanged. Compare with Courier and Times. (This may be due to the difference between Unicode's pre-v3.0 choice of representative glyphs, or the difference between French/English Apla=Didot/Porson's approaches.)

The console font configuration

According to MicroSoft, it is controlled by Registry hive

  HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont

The key 0 usually gives Lucida Console, and the key 00 gives Consolas. Adding random numbers does not work; however, if one adds one more zero (at least when adding to a sequence of zeros), one can add more fonts. You need to export this hive (e.g., use

  reg export "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont" console-ttf.reg

), save a copy (so you can always restore if the love goes sour) then edit the resulting file.

So if the maximal key with 0s is 00, add one extra row with an extra 0 at end, and the family name of your font. The "family name" is what the Font list in Control Panel shows for font families (a "stacked" icon is shown); for individual fonts the weight (Regular, Book, Bold etc) is appended. So I add a line

  "000"="DejaVu Sans Mono"

the result is (omitting Far Eastern fonts)

  Windows Registry Editor Version 5.00

  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont]
  "0"="Lucida Console"
  "000"="DejaVu Sans Mono"

The full file is in examples/console-fonts00-added.reg. After importing this file via reg (or give it as parameter to regedit; both require administrative priviledges) the font is immediately available in menu. (However, it does not work in "existing" console windows, only in newly created windows.)

(Do not use the example file directly. First inspect the hive exported on your system, and find the number of 0s to use. Then add a new line with correct number of zeros - as a value, one can use the string above. This will preserve the defaults of your setup. Keep in mind that selection-by-fontfamily is buggy: if you have more than one version of the font in different weight, it is a Russian Rullette which one of them will be taken (at least for DejaVu, which uses Book as the default weight). First install the "normal" flavor of the font, then do as above (so the system has no way of picking the wrong flavor!), and only after this install the remaining flavors.

CAVEAT: the string to put into Console\TrueTypeFont is the Family Name of the font. The family name is what is shown in the Fonts list of the Control Panel — but only for families with more than one font; otherwise the “metric name” of the font is appended.

On Windows, it is tricky to find the family name using the default Windows' tools, without inspecting the font in a font editor. One workaround is to select the font in Character Map application, then inspect HKEY_CURRENT_USER\Software\Microsoft\CharMap\Font via:

  reg export HKCU\Software\Microsoft\CharMap character-map-font.reg

Note: the mentioned above MicroSoft KB article lists the wrong way to find the family name. What is visible in the Properties dialogue of the font, and in CurrentVersion\Fonts is the Full Font Name. Fortunately, quite often the full name and the family name coincide — this is what happened with DejaVu. To find the "Full name" of the font, one can look into the hive

  HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts
  reg export "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts" fonts.reg

For example, after installing DejaVuSansMono.ttf, I see DejaVu Sans Mono (TrueType) as a key in this hive.

One more remark: for desktop icons coming from the “Public” user (“shared” icons) which start a console application, the default font is not directly editable. To reset it, one must:

There is no way to show Unicode contents on Windows

Until Firefox v13, one could use FireFox to show arbitrary Unicode text (limited only by which fonts are installed on your system). If you upgraded to a newer version, there is no (AFAIK) Windows program (for general public consumption) which would visualize Unicode text. The applications are limited either (in the worst case) by the characters supported by the currently selected font, or (in the best case) they can show additionally characters, but only those considered by the system as "important enough" (coming from a few of default fonts?).

There is a workaround for this major problem in FireFox (present at least up to v20). It is caused by this “improvement” which blatantly saves a few seconds of load time for a tiny minority of users, the price being an unability to show Unicode for everybody (compare with comments 33 and 75 on the bug report above).

It is not documented, but this action is controlled by about:config setting gfx.font_rendering.fallback.always_use_cmaps. To enable Unicode, make this setting into true (if you have it in the list as false, double-clicking it would do this — do search to determine this; otherwise you need to create a new Binary entry).

There is an alternative/additional way to enable extra fonts; it makes sense if you know a few character-rich fonts present on your system. The (undocumented) settings*.x-unicode (apparently) control fallback fonts for situations when a suitable font cannot be found via more specific settings. For example, when you installed (free) Deja vu, junicode, Symbola fonts on your system, you may set (these variables are not present by default; you need to create new String variables):   DejaVu Sans,Symbola,DejaVu Serif,DejaVu Sans Mono,Junicode        DejaVu Serif,Symbola,Junicode,DejaVu Sans,Symbola,DejaVu Sans Mono      Junicode,Symbola,DejaVu Sans,DejaVu Serif,DejaVu Sans Mono    DejaVu Sans Mono,DejaVu Sans,Symbola,DejaVu Serif,Junicode

And maybe also Fantasy      Symbola,DejaVu Serif,Junicode,DejaVu Sans Mono,DejaVu Sans

If you set both font.* variables with rich enough fonts, and gfx.font_rendering.fallback.always_use_cmaps, then you may have the best of both worlds: the situation when a character cannot be shown via font.* settings will be extremely rare, so the possiblity of delay due to gfx.font_rendering.fallback.always_use_cmaps is irrelevant.

Firefox misinterprets keypresses

Of these problems, Chrome has only Control-(Shift-)letter one, but a very cursory inspection shows other problems: Kana-arrows are not recognized as character-generating keys. (And IE9 just crashes in most of these situations…)

AltGr-keypresses triggering some actions

For example, newer versions of windows have graphics driver reacting on Ctrl-Alt-Arrows by rotating the screen. Usually, when you know which application is stealing your keypresses, one can find a way to disable or reconfigure this action.

For screen rotation: Right-Click on desktop, “Graphics Options”, “Hot Keys”, disable. The way to reconfigure this is to use “Graphics Properties” instead of “Graphics Options” (but this may depend on your graphics subsystem).

AltGr-keypresses going nowhere

Some AltGr-keypresses do not result in the corresponding letter on keyboard being inserted. It looks like they are stolen by some system-wide hotkeys. See:

If these keypresses would perform some action, one might be able to deduce how to disable the hotkeys. So the real problem comes when the keypress is silently dropped.

I found out one scenario how this might happen, and how to fix this particular situation. (Unfortunately, it did not fix what I see, when AltGr-s [but not AltGr-S] is stolen.) Installing a shortcut, one can associate a hotkey to the shortcut. Unfortunately, the UI allows (and encourages!) hotkeys of the form <Control-Alt-letter> (which are equivalent to AltGr-letter) - instead of safe combinations like Control-Alt-F4 or Alt-Shift-letter (which — by convention — are ignored by keyboard drivers, and do not generate characters). If/when an application linked to by this shortcut is gone, the hotkey remains, but now it does nothing (no warning or dialogue comes).

If the shortcut is installed in one of "standard places", one can find it. Save this to K:\findhotkey.vbs (replace K: by the suitable drive letter here and below)

  on error resume next
  set WshShell = WScript.CreateObject("WScript.Shell")
  Dim A
  Dim Ag
  Set Ag=Wscript.Arguments
  If Ag.Count > 0 then
    For x = 0 to Ag.Count -1
      A = A & Ag(x)
  End If
  Set FSO = CreateObject("Scripting.FileSystemObject")
  set lnk = WshShell.CreateShortcut(A)
  If lnk.hotkey <> "" then
    msgbox A & vbcrlf & lnk.hotkey
  End If

Save this to K:\findhotkey.cmd

  set findhotkey=k:\findhotkey
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
  cd /d %UserProfile%\desktop
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
  cd /d %AllUsersProfile%\desktop
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
  cd /d %UserProfile%\Start Menu
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
  cd /d %AllUsersProfile%\Start Menu
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
  cd /d %APPDATA%
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.lnk) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.pif) do %findhotkey%.vbs "%%A"
    for /r %%A in (*.url) do %findhotkey%.vbs "%%A"

(In most situations, only the section after the last cd /d is important; in my configuration all the "interesting" stuff is in %APPDATA%. Running this should find all shortcuts which define hot keys.

Run the cmd file. Repeat in the "All users"/"Public" directory. It should show a dialogue for every shortcut with a hotkey it finds. (But, as I said, it did not fix my problem: AltGr-s works in MSKLC test window, and nowhere else I tried...)

Control-Shift-keypresses starting bloatware applications

(Seen on IdeaPad.) Some pre-installed programs may steal Control-Shift-keypresses; it may be hard to understand what is the name of the application even when the stealing results in user-visible changes.

One way to deal with it is to start Task Manager in Processes (or Details) panel, and click on CPU column until one gets decreasing-order of CPU percentage. Then one can try to detect which process is becoming active by watching top rows when the action happens (or when one manages to get back to the desktop from the full-screen bloatware); one may need to repeat triggering this action several times in a row. After you know the name of executable, you can google to find out how to disable it, and/or whether it is safe to kill this process.

Example: On IdeaPad, it was TouchZone.exe (safe to kill). It was stealing Control-Shift-R and Control-Shift-T.

WINDOWS GOTCHAS for keyboard developers using MSKLC ^

Several similar MSKLC created keyboards may confuse the system

Apparently, the system may get majorly confused when the description of the project gets changed without changing the DLL (=project) name.

(Tested only with Win7 and the name in the DESCRIPTIONS section coinciding with the name on the KBD line - both in *.klc file.)

The symptoms: I know how one can get 4 different lists of keyboards:

  1. Click on the keyboard icon in the Language Bar - usually shown on the toolbar; positioned to the right of the language code EN/RU etc (keyboard icon is not shown if only one keyboard is associated to the current language).
  2. Go to the Input Language settings (e.g., right-click on the Language bar, Settings, General.

  3. on this General page, press Add button, go to the language in question.

  4. Check the .klc files for recently installed Input Languages.

  5. In MS Keyboard Layout Creator, go to File/Load Existing Keyboard list.

It looks like the first 4 get in sync if one deletes all related keyboards, then installs the necessary subset. I do not know how to fix 5 - MSKLC continues to show the old name for this project.

Another symptom: Current language indicator (like EN) on the language bar disappears. (Reboot time?)

Is it related to ***\Local Settings\MuiCache\*** hive???

Possible workaround: manually remove the entry in HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Keyboard Layouts (the last 4 digits match the codepage in the .klc file).

Too long description (or funny characters in description?)

If the name in the DESCRIPTIONS section is too long, the name shown in the list 2 above may be empty.

(Checked only on Win7 and when the name in the DESCRIPTIONS section coincides with the name on the KBD line - both in *.klc file.)

(Fixed by shortening the name [but see "Several similar MSKLC created keyboards may confuse the system" above!], so maybe it was not the length but some particular character (+?) which was confusing the system. (I saw a report on MSKLC bug when description had apostroph character '.)

MSKLC ruins names of dead key when reading a .klc

When reading a .klc file, MS Keyboard Layout Creator may ruin the names of dead keys. Symptom: open the dialogue for a dead key mapping (click the key, check that Dead key view has checkmark, click on the ... button near the Dead key? checkbox); then the name (the first entry field) contains some junk. (Looks like a long ASCII string

   U+0030 U+0030 U+0061 U+0039


Workaround: if all one needs is to compile a .klc, one can run KBDUTOOL directly.

Workaround: correct ALL these names manually in MSKLC. If the names are the Unicode name for the dead character, just click the Default button near the entry field. Do this for ALL the dead keys in all the registers (including SPACE!). If CapsLock is not made "semantically meaningful", there are 6 views of the keyboard (PLAIN, Ctrl, Ctrl+Shift, Shift, AltGr, AltGr+Shift) - check them all for grayed out keys (=deadkeys).

Check for success: File/"Save Source File As, use a temporary name. Inspect near the end of the generated .klc file. If OK, you can go to the Project/Build menu. (Likewise, this way lets you find which deadkey's names need to be fixed.)

!!! This is time-consuming !!! Make sure that other things are OK before you do this (by Project/Validate, Project/Test).

BTW: It might be that this is cosmetic only. I do not know any bad effect - but I did not try to use any tool with visual feedback on the currently active sub-layout of keyboard.

Double bug in KBDUTOOL with dead characters above 0x0fff

This line in .klc file is treated correctly by MSKLC's builtin keyboard tester:

  39 SPACE 0 0020 00a0@ 0020 2009@ 200a@ //  ,  ,  ,  ,   // SPACE, NO-BREAK SPACE, SPACE, THIN SPACE, HAIR SPACE

However, via kbdutool it produces the following two bugs:

  static ALLOC_SECTION_LDATA MODIFIERS CharModifiers = {
    //  Modification# //  Keys Pressed
    //  ============= // =============
        0,            // 
        1,            // Shift 
        2,            // Control 
        SHFT_INVALID, // Shift + Control 
        SHFT_INVALID, // Menu 
        SHFT_INVALID, // Shift + Menu 
        3,            // Control + Menu 
        4             // Shift + Control + Menu 
    {VK_SPACE     ,0      ,' '      ,WCH_DEAD ,' '      ,WCH_LGTR ,WCH_LGTR },
    {0xff         ,0      ,WCH_NONE ,0x00a0   ,WCH_NONE ,WCH_NONE ,WCH_NONE },
  static ALLOC_SECTION_LDATA LIGATURE2 aLigature[] = {
    {VK_SPACE     ,6      ,0x2009   ,0x2009   },
    {VK_SPACE     ,7      ,0x200a   ,0x200a   },

Essentially, 2009@ 200a@ produce LIGATURES (= multiple 16-bit chars) instead of deadkeys. Moreover, these ligatures are put on non-existing "modifications" 6, 7 (the maximal modification defined is 4; so the code uses the Shift + Control + Menu flags instead of "modification number" in the ligatures table.

MSKLC keyboards handle Ctrl-Shift-letter, Ctrl-@ (x00) , Ctrl-^ (x1e) and Ctrl-_ (x1f) differently than US keyboard

The US keyboard produces (as the “string value”) the corresponding Control-letter when Ctrl-Shift-letter is pressed. (In console applications, \x00 is not visible.) MSKLC does not reproduces this behaviour. This may break an application if it was not specifically tested with “complicated” keyboards.

The only way to fix this from the “naive” keyboard layout DLL (i.e., the kind that MSKLC generates) which I found is to explicitly include Ctrl-Shift as a handled combination, and return Ctrl-letter on such keypresses. (This is enabled in the generated keyboards generated by this module - not customizable in v0.12.)

"There was a problem loading the file" from MSKLC

Make line endings in .klc DOSish.

AltGr-keys do not work

Make line endings in .klc DOSish (when given as input to kbdutool - it gives no error messages, and deadkeys work [?!]).

Error 2011 (ooo-us, line 33): There are not enough columns in the layout list.

The maximal line end of kbdutool is exceeded (a line or two ahead). Try remoing inline comments. If helps, change he workflow to cut off long lines (250 bytes is OK).

Error 2012 (ooo-us-shorten.klc, line 115):

    <ScanCode e065 - too many scancodes here to parse.>

from MSKLC. This means that the internal table of virtual keys mapped to non-e0 (sic!) scancodes is overloaded.

Time to switch to direct generation of .c file? Or you need to triage the “added” virtual keys, and decide which are less important so you can delete them from the .klc file.

Only the first 8 with-modifiers columns are processed by kbdutool

Time to switch to direct generation of .c file?

Only the first digit of the which-modifier-column is output by kbdutool in LIGATURES

Time to switch to direct generation of .c file?

kbdutool produces KEYNAME_DEAD section with meaningless entries for prefix keys 0x08, 0x0A, 0x0D

These entries do not stop keyboard from working. They look like L"'\b'" L"Name is here…"...

Time to switch to direct generation of .c file?

It is not clear how to compile .C files emitted by kbdutool.exe

This distribution includes a script examples/compile_link_kbd.cmd which can do this. It is inspired by

It allows us to build using the cycle

(This assumes that the installer was already built by MSKLC using a “simplified-to-nothing” .klc file which does not trigger the MSKLC bugs).

(See also

kbdutool cannot ignore column=15 of the keybinding definition table

(Compare with "Windows ignores column=15 of the keybinding definition table".)

kbdutool requires that all the columns are associated to a modifier-bitmap. But column=15 should not be associated to any.

The workaround is to associate it to the bitmap which should not be bound to any column (like 4=KBDALT). In the output .C file, one would have 15 instead of SHFT_INVALID for the bitmap 4, but SHFT_INVALID is defined to be 15 anyway…

kbdutool ignores bits above 0x20 in the modification columns descriptor

Time to switch to direct generation of .C files?

kbdutool cannot assign more than one bitmask to a modification column

Time to switch to direct generation of .C files?

(Quite often, one combination of modifiers should produce the same characters as another one. The format of keyboard layout tables allows them to share a modification column. The format of .klc files does not allow sharing.)

kbdutool forgets to emit aVkToWch3/6/8

If the .klc file has many modification columns, the emitted aVkToWcharTable contains only aVkToWch1/2.

WINDOWS GOTCHAS for keyboard developers (problems in kernel) ^

It is hard to understand what a keyboard really does

To inspect the output of the keyboard in the console mode (may be 8-bit, depending on how Perl is compiled), one can run

  perl -MWin32::Console -wle 0 || cpan install Win32::Console
  perl -we "sub mode2s($){my $in = shift; my @o; $in & (1<<$_) and push @o, (qw(rAlt lAlt rCtrl lCtrl Shft NumL ScrL CapL Enh ? ??))[$_] for 0..10; qq(@o)} use Win32::Console; my $c = Win32::Console->new( STD_INPUT_HANDLE); my @k = qw(T down rep vkey vscan ch ctrl); for (1..20) {my @in = $c->Input; print qq($k[$_]=), ($in[$_] < 0 ? $in[$_] + 256 : $in[$_]), q(; ) for 0..$#in; print(@in ? mode2s $in[-1] : q(empty)); print qq(\n)}"

This installs Win32::Console module (if needed; included with ActiveState Perl) then reports 20 following console events (press and keep Alt key to exit by generating a “harmless” chain of events). Limitations: the reported input character is not processed (via ToUnicode(); hence chained keys and multiple chars per key are reported only as low-level), and is reported as a signed 8-bit integer (so the report for above-8bit characters is completely meaningless).

  T=1; down=1; rep=1; vkey=65; vscan=30; ch=240; ctrl=9; rAlt lCtrl
  T=1; down=0; rep=1; vkey=65; vscan=30; ch=240; ctrl=9; rAlt lCtrl

This reports single (T=1) events for keypress/keyrelease (down=1/0) of AltGr-a. One can see that AltGr generates rAlt lCtrl modifiers (this is just a transcription of ctrl=9, that a is on virtual key 65 (this is VK_A) with virtual scancode 30, and that the generated character (it was æ) is 240.

The character is approximated to the current codepage. For example, this is Kana-b entering β = U+03b2 in codepage cp1252:

  T=1; down=1; rep=1; vkey=66; vscan=48; ch=223; ctrl=0;
  T=1; down=0; rep=1; vkey=66; vscan=48; ch=223; ctrl=0;

Note that 223 = 0xDF, and U+00DF = ß. So beta is substituted by eszet.

There is also a script examples/ in this distribution which does a little bit more than this. One can also give this script the argument U (or Un, where n is the 0-based number among the listed keyboard layouts) to report ToUnicode() results, or argument cooked to report what is produced by reading raw charactes (as opposed to events) from the console.

It is not documented how to make a with-prefix-key(s) combination produce 0-length string

Use 0000@ (in .klc), or DEADKEY 0 in a .c file. Explanation: what a prefix key is doing is making the kernel remember a word (the state of the finite automaton), and not producing any output character. Having no prefix key corresponds to the state being 0.

Hence makeing prefix_key=0 is the same as switching the finite automaton to the initial state, and not producing any character — and this exactly what is requested in the question.

If data in KEYNAME_DEAD takes too much space, keyboard is mis-installed, and “Language Bar” goes crazy

Installation reports success, the keyboard appears in the list in the Language Bar's "Settings". But the keyboard is not listed in the menu of the Language Bar itself.

Deinstalling (by MSKLC's installer) in such a case removes one (apparently, last) of the listed keyboards for the language; at least it is removed from the menu of the Language Bar itself. However, the list in the “Settings” does not change! One can't restore the (wrongly) removed (unrelated!) layout by manipulating the latter list. (I did not try to check what will happen if only one keyboard for the language is available — is it removed for good?.)

I did not find a way to restore the deleted keyboard. Experimenting with these is kinda painful: with each failure, I add one extra keyboard to the list in the “Settings”; - so the list is growing and growing! [Better add useless-to-you keyboards, since there may be a chance you will never be able to install them again. Maybe a reboot will fix it?]

Update: this condition reappeared in update from v0.61 to v0.63 of izKeys layouts. Between these versions, there was a very small increment of the size: one modification column was added, and two deadkeys were added. Removing a bunch of (useless?) dead keys descriptions fixed this again; but now I have my doubts on whether it was due to ONLY increasing the size of KEYNAME_DEAD… Maybe it is due to the total size of certain segments in the DLL.

Windows ignores column=15 of the keybinding definition table

Note that 15 is SHFT_INVALID; this column number is used to indicate that this particular combination of modifiers does not produce keys. In particular, the generator must avoid this column number.

Workaround: put junk into this column, and use different columns for useful modifier combinations. The mapping from modifiers to columns should not be necessarily 1-to-1. (But see "kbdutool cannot ignore column=15 of the keybinding definition table".)

Windows combines modifier bitmaps for lCtrl, Alt and rAlt on AltGr

(At least when AltGr is special in the keyboard,) the modifier bitmap bound to this key is actually bit-or of bitmaps above. Essentially, this prohibits assigning interesting flag combinations to lCtrl.

The (very limited) workaround is to ensure that the flags one puts on AltGr contain all the flags assigned to the above VK codes. (This does not change anything, but at least makes the assignments less confusing for human inspection.)

Windows ignores lAlt if its modifier bitmaps is not standard

Adding KBDROYA to lAlt disables console sending non-modified char on keydown. Together with the previous problem, this looks like essentially prohibiting putting interesting bitmaps on the left modifier keys.

Workaround: one can add KBDKANA on lAlt. It looks like the combination KBDALT|KBDKANA is compatible with Windows' handling of Alt (both in console, and for accessing/highlighting the menu entries). (However, since only KBDALT is going to be stripped for handling of lAlt-key, the modification column for KBDKANA should duplicate the modification column for no-KBD-flags. Same with KBDSHIFT added.)

When AltGr produces ROYA, problems in Notepad

Going to the Save As dialogue in Notepad loses "speciality of AltGr" (it highlights Menu); one need to switch layouts via LAlt+LShift to restore.

I do not know any workaround.

Console applications cannot detect when a keypress may be interpreted as a “command”

The typical logic of an (advanced) application is that it interprets certain keypresses (combinations of keys with modifiers) as “commands”. To do this in presence of user-switchable keyboards, when it is not known in compile time which key sequences generate characters, the application must be able to find at runtime which keypresses are characters-generating, and which are not. The latter keypresses are candidates to be checked whether they should trigger commands of the application.

For final keypresses of a character-generating key-sequence, an application gets a notification from the ReadConsoleEvent() API call that this keypress generates a character. However, for the keypresses of the sequence which are non the last one (“dead” keys), there is no such notification.

Therefore, there is no way to avoid dead keys triggering actions in an application. What is the difference with non-console applications? First of all, they get such a notification (with the standard TranslateMessage()/DispatchMessage() sequence of API calls, on WM_KEYDOWN, one can PeekMessage() for WM_SYSDEADCHAR/WM_DEADCHAR and/or WM_SYSCHAR/WM_CHAR). Second, the windowed application may call ToUnicode(Ex)() to calculate this information itself.

Well, why a console application cannot use the second method? First, the active keyboard layout of a console application is the default one. When user switches the keyboard layout of the console, the application gets no notification of this, and its keyboard layout does not change. This makes ToUnicode() useless. Moreover, due to security architecture, the console application cannot query the ID of the thread serving the message loop of the console, so cannot query GetKeyboardLayout() of this thread. Hence ToUnicodeEx() is useless too.

(There may be a lousy workaround: run ToUnicodeEx() on all the installed keyboard layouts, and check which of them are excluded by comparing with results of ReadConsoleEvent(). Interpret contradictions as user changing the keyboard layout. Of course, on several keypresses following a change of keyboard layout one may get unexpected results. And if two similar keyboards are installed, one may also never get definite answer on which of them is currently active.)

(To handle this workaround, one must have a way to call ToUnicode() in a way which does not change the internal state of the keyboard driver. Observe:

Behaviour of Alt-Modifiers-Key vs Modifiers-Key

When both combinations produce characters (say, X and Y), it is not clear how an application shouild decide whether it got Alt-Y event (for menu entry starting with Y), or an X event.

A partial workaround (if the semantic of the layout fits into the limited number of bits in the ORed mask): make all the keys which may be combined with Alt to have the KBDCTRL bit in the mask set; add some extra bit to Ctrl keys to be able to distinguish them. Then at least the kernel will produce the correct character on the ToUnicode() call (hence in TranslateMessage()). [A potential that an application may be confused is still large.]

Customization of what CapsLock is doing is very limited

(See the description of the semantic of CapsLock in "Keyboard input on Windows, Part II: The semantic of ToUnicode()".)

A partial workaround (if the semantic of the layout fits into the limited number of bits in the ORed mask): make all the modifier combinations (except for the base layer) to have KBDCTRL and KBDALT bits set; add some extra bits to Ctrl keys and Alt keys (apparently, only KBDKANA will work with Alt) to be able to distinguish them. Then the CAPLOKALTGR flag will affect all these combinations too.

lCtrl-rCtrl combination: multiple problems

First of all, sometimes Shift is ignored when used with this combination. (Fixed by reboot.)

(Does not work also with combinations with lAlt and/or Menu). On the other hand, CapsLock works as intended. (I even got an impression that sometimes Shift works when CapsLock is active; cannot reproduce this, though.)

I suspect this is related to the binding of Shift-Ctrl to switch between keyboards of a language suddently jumpting to existence (without my interaction). Simultaneously, this option disappeared from the UI to change keyboard options ("Settings/Advanced Key Settings" in Language Bar in Windows 7). I might be that press/release of Shift is filtered out in presence of lCtrl-rCtrl?

(I also saw what looks like Menu key being stuck in some situations — fixed by pressing it again. Do not know how to reproduce this. It is interesting to note that one of the bits in the mask of the Menu key is 0x80, and there is a define for this bit in kbd.h named KBDGRPSELTAP — but it is undocumented, and, judging by names, one might think that KBDGRPSELTAP would work in pair with the flag GRPSELTAP of VK_TO_WCHARSn-Attributes>.)

NOTES: Apparently, lCtrl+rCtrl+NUMPADchar do not work — neither with nor without NumLock. Key up/down for Z/X/C/V/M/,/. are not delivered here when used with lCtrl+rCtrl modifiers (at least in a console). Adding Shift/lAlt/Menu does not change this. Same for F1/F2/F8/F9 and Enter/Insert/Delete/Home/PgUp (but not for keypad ones!).

No workarounds are known.

On principles of intuitive design of Latin keyboard ^

Some common (meaning: from Latin-1-10 of ISO 8859) Latin alphabet letters are not composed (at least not by using 3 simplest modifiers out of 8 modifiers). We mean ÆÐÞÇIJØŒß (and ¡¿ for non-alphatetical symbols). It is crucial that they may be entered by an intuitively clear key of the keyboard. There is an obvious ASCII letter associated to each of these (e.g., T associated to the thorn Þ), and in the best world just pressing this letter with AltGr-modifier would produce the desired symbol.

  But what to do with ª,º?

There is only one conflict: both Ø,Œ "want" to be entered as AltGr-O; this is the ONLY piece of arbitrariness in the design so far. After resolving this conflict, AltGr-keys !ASDCTIO? are assigned their meanings, and cannot carry other letters (call them "stuck in stone keys").

(Other keys "stuck in stone" are dead keys: it is important to have the glyph etched on these keyboard's keys similar to the task they perform.)

Then there are several non-alphabetical symbols accessible through ISO 8859 encodings. Assigning them AltGr- access is another task to perform. Some of these symbols come in pairs, such as ≤≥, «», ‹›, “”, ‘’; it makes sense to assign them to paired keyboard's keys: <> or [] or ().

However, this task is in conflict of interests with the following task, so let us explain the needs answered by that task first.

One can always enter accented letters using dead keys; but many people desire a quickier way to access them, by just pressing AltGr-key (possibly with shift). The most primitive keyboard designs (such as IBM International,

) omit this step and assign only the NECESSARY letters for AltGr- access. (Others, like MicroSoft International, assign only a very small set.)

This problem breaks into two tasks, choosing a repertoir of letters which will be typable this way, and map them to the keys of the keyboard. For example, EurKey choses to use ´¨`-accented characters AEUIO (except for ), plus ÅÑ; MicroSoft International does ÄÅÉÚÍÓÖÁÑß only (and IBM International does none); Bepo does only ÉÈÀÙŸ (but also has the Azeri Ə available - which is not in ISO 8819 - and has Ê on the 105th key "2nd \|"), Mac Extended has only ÝŸ (?!)                                       # old version of .klc
                or look for "a graphic of the special characters" on

Keyboards on Mac: Tool to produce:

Our solution

First, the answer:

Rule 0:

letters which are not accented by `´¨˜ˆˇ°¯ are entered by AltGr-keys "obviously associated" to them. Supported: ÆÐÞÇIJØß.

Rule 0a:

Same is applicable to Ê and Ñ.

Rule 1:

Vowels AEYUIO accented by `´¨ are assigned the so called "natural position": 3 Bottom row of keyboard are allocated to accents (¨ is the top, ´ is the middle, ` is the bottom row of 3 letter-rows on keyboard - so À is on ZXCV-row), and are on the same diagonal as the base letter. For left-hand vowels (A,E) the diagonal is in the direction of \, for right hand voweles (Y,U,I,O) - in the direction of /.

Rule 1a:

If the "natural position" is occupied, the neighbor key in the direction of "the other diagonal" is chosen. (So for A,E it is the /-diagonal, and for right-hand vowels YUIO it is the \-diag.)

Rule 1b:

The neighbor key is down unless the key is on bottom row - then it is up.

Supported by rules "1": all but ÏËỲ.

Rule 2:

Additionally, Å,Œ,Ì are available on keys R,P,V.


If you remember only Rule 0, you still can enter all Latin-1 letter using Rule 0; all you need to memorize are dead keys: `';~6^7& for `´¨˜ˆˇ°¯ on EurKey keyboard (but better locations ARE possible).

   (What the rule 0 actually says is: "You do not need to memorize me". ;-)

If all you remember are rules 1,1a, you can calculate the position of the AltGr-key for AEYUIO accented by `´¨ up to a choice of 3 keys (the "natural key" and its 2 neighbors) - which are quick to try all if you forgot the precise position. If you remember rules 1,1ab, then this choice is down to 2 possible candidates.

Essentially, all you must remember in details is that the "natural positions" form a V-shape # - \ on left, / on right, and in case of bad luck you should move in the direction of other diagonal one step. Then a letter is either in its "obvious position", or in one of 3 modifications of the natural position". Only Å and Œ need a special memorization.


It is important to have a logical way to quickly understand whether a letter is quickly accessible from a keyboard, and on which key (or, maybe, to find a small set of keys on which a letter may be present - then, if one forgets, it is possible to quickly un-forget by trying a small number of keys).

The idea: we assign alphabetical Latin symbols only to alphabetical keys on the keyboard; this way we can use (pared) symbol keys to enter pared Unicode symbols. Now consider diagonals on the alphabetic part of the keyboard: \-diagonals (like EDC) and /-diagonals (like UHB). Each diagonal contains 3 (or less) alphabetic keys; we WANT to assign ¨-accent to the top one, ´-accent to the middle one, and `-accent to the bottom one.

On the left-hand part of the keyboard, use \-diagonals, on the right-hand part use /-diagonals; now each diagonal contains EXACTLY 3 alphabetic keys. Moreover, the diagonals which contain vowels AEYUIO do not intersect.

If we have not decided to have keys set in stone, this would be all - we would get "completely predictable" access to ´¨`-accented characters AEUIO. For example, Ÿ would be accessible on AltGr-Y, Ý on AltGr-G, Ỳ on AltGr-V. Unfortunately, the diagonals contain keys ASDCIO set in stone. So we need a way to "move away" from these keys. The rule is very simple: we move one step away in the direction of "other" diagonal (/-diagonal on the left half, and \-diagonal on the right half) one step down (unless we start on keys A, C where "down" is impossible and we move up to W or F).

Examples: Ä is on Q, Á "wants to be" on A (used for Æ), so it is moved to W; Ö wants to be on O (already used for Ø or Œ), and is moved away to L; È wants to be on C (occupied by Ç), but is moved away to F.

There is no way to enter Ï using this layout (unless we agree to move it to the "8*" key, which may conflict with convenience of entering typographic quotation marks). Fortunately, this letter is rare (comparing even to Ë which is quite frequent in Dutch). So there is no big deal that it is not available for "handy" input - remember that one can always use deadkeys.

Note that the keys "P" and "R" are not engaged by this layout; since "P" is a neighbor of "O", it is natural to use it to resolve the conflict between Ø or Œ (which both want to be set in stone on "O"). This leaves only the key "R" unengaged; but what we do not cover are two keys Å and Ñ which are relatively frequent in Latin-derived European languages.

Note that Ì is moderately frequent in Italian, but Ñ is much more frequent in Spanish. Since Ì occupies the key which on many keyboards is taken by Ñ, maybe it makes sense to switch them... Likewise, Ê is much more frequent than Ë; switch them.


U-caron: ǔ, Ǔ which is used to indicate u in the third tone of Chinese language pinyin. But U-breve is used in Latin encodings. Ǧ/ǧ (G with caron) is used, but only in "exotic" or old languages (has no combined form - while G-breve is in Latin encodings. A-breve Ă: A-caron Ǎ is not in Latin-N; apparently, is used only in pinyin, zarma, Hokkien, vietnamese, IPA, transliteration of Old Latin, Bible and Cyrillic's big yus.

In EurKey: only a takes breve, the rest take caron (including G but not U)

out of accents ° and dot-accent ˙ in Latin-N: only A and U take °, and they do not take dot-accent. In EurKey: also small w,y take ring accent; same in Bepo - but they do not take dot accent in Latin-N.

Double-´ and cornu (both on a,u only) can be taken by ¨ or ˙ on letters with ¨ already present (in Unicode ¨ is not precombined with diaeresis or dots). But one must special-case Ë and Ï and Ø (have Ê and IJ instead; IJ takes no accents, but Ê takes acute, grave, tilde and dot below...).! Æ takes acute and macron; Ø takes acute.

Actually, cornu=horn is only on o,u, so using dot/ring on ö and ü is very viable...

So for using AltGr-letter after deadkeys: diaresis can take dot above, hat and wedge, diaresis. Likewise, ` and ´ are not precombined together (but there is a combined combining mark). So one can do something else on vowels (ogonek?).

Applying ´ to `-accented forms: we do not have `y, so must use "the natural position" which is mixed with Ñ (takes no accents) and Ç (takes acute!!!).

s, t do not precombine with `; so can use for the "alternative cedilla".

Only auwy take ring, and they do not take cedilla. Can merge.

Bepo's hook above; ảɓƈɗẻểƒɠɦỉƙɱỏƥʠʂɚƭủʋⱳƴỷȥ ẢƁƇƊẺỂƑƓỈƘⱮỎƤƬỦƲⱲƳỶȤ perl -wlnae "next unless /HOOK/; push @F, shift @F; print qq(@F)" NamesList.txt | sort | less Of capital letters only T and Y take different kinds of hooks... (And for T both are in Latin-Extended-B...)

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