<rng:element name="memberOf">
<rng:ref name="att.global.attributes"/>
<rng:optional>
<rng:attribute name="key">
<rng:ref name="data.name"/>
</rng:attribute>
</rng:optional>
<rng:optional>
<rng:attribute name="mode" a:defaultValue="add">
<rng:choice>
<rng:value>add</rng:value>
<rng:value>delete</rng:value>
</rng:choice>
</rng:attribute>
</rng:optional>
<rng:ref name="macro.xtext"/>
</rng:element>
element memberOf
{
att.global.attributes,
attribute key { data.name }?,
attribute mode { "add" | "delete" }?,
macro.xtext
}