<xs:documentation>
Any top-level, optional element is allowed to appear more
than once - Any extensibility element is allowed in any place.
Such extensibility elements must be in the substitution group of
globalExt or postTypes
</xs:documentation>
<xs:documentation>
Either the element attribute OR the type attribute may appear but not both.
Alternatively a qualified extensibility attribute which refers to constructs
in some type system other than XML Schema may be used.
</xs:documentation>
<xs:documentation>
This abstract type is intended to serve as the base type for
extensibility elements. It includes the wsdl:required attribute
which it is anticipated will be used by most extension elements
</xs:documentation>