<!yatt:args foo>
<h2>request sigil mapping</h2>
<form method="POST">
<input type="text" name="foo" size="10" value="&yatt:foo;">
<input type="submit" name="~" value="show this">
<input type="submit" name="~bar" value="show bar">
<input type="submit" name="!baz" value="do baz">
</form>

<!yatt:page bar foo>
<h2>page bar</h2>
foo=&yatt:foo;

<!yatt:action baz>
my ($this, $con) = @_;
print $con "OK. foo=", map {defined $_ ? $_ : "(NULL)"} $con->param('foo');

<!yatt:page testlistarg chklst=list>
checked=
<yatt:foreach my=v list=chklst>&yatt:v;
</yatt:foreach>.