Mixed key signatures, e.g. those consisting of a mixture of flats and sharps (Read, p. 143, ex. 9-39), and key signatures with unorthodox placement of the accidentals (Read, p. 141) can be encoded using the keySig element.
<classSpec ident="att.keySigDefault.log" module="MEI.shared" type="atts">
<desc>Used by staffDef and scoreDef to provide default values for attributes in the logical
domain that are related to key signatures.</desc>
<attList org="group">
<attDef ident="key.sig" usage="opt">
<desc>Written key signature.</desc>
</attDef>
</attList>
<remarks>
<p part="N">Mixed key signatures, e.g. those consisting of a mixture of flats and sharps (Read,
p. 143,
ex. 9-39), and key signatures with unorthodox placement of the accidentals (Read,
p. 141)
can be encoded using the
<gi scheme="MEI">keySig</gi> element.</p>
</remarks>
</classSpec>