IDREFDatatypeValidator - represents the IDREFS
attribute type from XML 1.1 recommendation. The
Value Space of IDREF is the set of all strings
that match the NCName production and have been
used in an XML Document as the value of an element
or attribute of Type ID. The Lexical space of
IDREF is the set of strings that match the NCName
production.
The Value space of IDREF is scoped to a specific
instance document |