2.2.5.14 dsc:MimeExtensionPatternType

The dsc:MimeExtensionPatternType type restricts built-in type xs:NMTOKEN (as specified in [XMLSCHEMA1] and [XMLSCHEMA2]) with a pattern based on a regular expression that allows extensible keywords.

 <xs:simpleType name="MimeExtensionPatternType">
     <xs:restriction base="xs:NMTOKEN">
         <xs:pattern value="\w+[\w:/;_\-\\\+\.]*"/>
     </xs:restriction>
 </xs:simpleType>