A cancel element indicates that the old key signature should be cancelled before the new one appears. This will always happen when changing to C major or A minor and need not be specified then. The cancel value matches the fifths value of the cancelled key signature (e.g., a cancel of -2 will provide an explicit cancellation for changing from B flat major to F major). The optional location attribute indicates whether the cancellation appears to the left or the right of the new key signature. It is left by default.
<xs:complexType name="cancel"><xs:annotation><xs:documentation>A cancel element indicates that the old key signature should be cancelled before the new one appears. This will always happen when changing to C major or A minor and need not be specified then. The cancel value matches the fifths value of the cancelled key signature (e.g., a cancel of -2 will provide an explicit cancellation for changing from B flat major to F major). The optional location attribute indicates whether the cancellation appears to the left or the right of the new key signature. It is left by default.</xs:documentation></xs:annotation><xs:simpleContent><xs:extension base="xs:integer"><xs:attribute name="location" type="left-right"/></xs:extension></xs:simpleContent></xs:complexType>