The start-stop-continue type is used for an attribute of musical elements that can either start or stop, but also need to refer to an intermediate point in the symbol, as for complex slurs.
<xs:simpleType name="start-stop-continue"><xs:annotation><xs:documentation>The start-stop-continue type is used for an attribute of musical elements that can either start or stop, but also need to refer to an intermediate point in the symbol, as for complex slurs.</xs:documentation></xs:annotation><xs:restriction base="xs:token"><xs:enumeration value="start"/><xs:enumeration value="stop"/><xs:enumeration value="continue"/></xs:restriction></xs:simpleType>