<?xml version="1.0" encoding="UTF-8"?>
<!-- 
  PICA XML 1.0 - XML Schema for XML representation of PICA data
  Author: Jakob Voss <jakob.voss@gbv.de>
  Date: 2009-07-06
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
  targetNamespace="info:srw/schema/5/picaXML-v1.0" 
  xmlns="info:srw/schema/5/picaXML-v1.0">
  
  <xs:element name="collection">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="1" maxOccurs="unbounded" ref="record"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  
  <xs:element name="record" >
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="1" maxOccurs="unbounded" ref="datafield"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  
  <xs:element name="datafield">
    <xs:complexType>
      <xs:sequence>
        <xs:element minOccurs="1" maxOccurs="unbounded" ref="subfield"/>
      </xs:sequence>
      <xs:attribute name="tag" use="required">
        <xs:simpleType>
          <xs:restriction base="xs:string">
            <xs:pattern value="[0-9][0-9][0-9][A-Z@]"/>
          </xs:restriction>
        </xs:simpleType>    
      </xs:attribute>
      <xs:attribute name="occurrence" use="optional">
        <xs:simpleType>
          <xs:restriction base="xs:string">
            <xs:pattern value="[0-9][0-9]"/>
          </xs:restriction>
        </xs:simpleType>    
      </xs:attribute>      
    </xs:complexType>
  </xs:element>
  
  <xs:element name="subfield">
    <xs:complexType mixed="true">
      <xs:attribute name="code" use="required">
        <xs:simpleType>
          <xs:restriction base="xs:string">
            <xs:pattern value="[0-9A-Za-z]"/>
          </xs:restriction>
        </xs:simpleType>    
      </xs:attribute>      
    </xs:complexType>
  </xs:element>
  
</xs:schema>