<sch:rule context="mei:*[@notationsubtype]">
<sch:assert test="@notationtype">An element with a notationsubtype attribute must have
a notationtype attribute.</sch:assert>
</sch:rule>
<classSpec ident="att.notationType" module="MEI" type="atts">
<desc>Attributes that provide for classification of notation.</desc>
<attList org="group">
<attDef ident="notationtype" usage="opt">
<desc>Contains classification of the notation contained or described by the element bearing
this attribute.</desc>
</attDef>
<attDef ident="notationsubtype" usage="opt">
<desc>Provides any sub-classification of the notation contained or described by the element,
additional to that given by its notationtype attribute.</desc>
<datatype maxOccurs="1" minOccurs="1">
<rng:data type="NMTOKEN"/>
</datatype>
<constraintSpec ident="When_notationsubtype" scheme="isoschematron">
<constraint>
<sch:rule context="mei:*[@notationsubtype]">
<sch:assert test="@notationtype">An element with a notationsubtype attribute must have
a notationtype attribute.</sch:assert>
</sch:rule>
</constraint>
</constraintSpec>
</attDef>
</attList>
</classSpec>