yes-no-number 

The yes-no-number type is used for attributes that can be either boolean or numeric values.

Simple Type Information

Used By

Attributes sound/@damper-pedal, sound/@soft-pedal, sound/@sostenuto-pedal

Source 

<xs:simpleType name="yes-no-number">
  <xs:annotation>
    <xs:documentation>The yes-no-number type is used for attributes that can be either boolean or numeric values.</xs:documentation>
  </xs:annotation>
  <xs:union memberTypes="yes-no xs:decimal"/>
</xs:simpleType>