significant property as pointer

Is there a published significant property, which can contain as value
(=range)an uri, which identifies a XML schema?

Suppose I have some resource (=Class), which could have syntactical
definition used XML Schema. Now I want to reference to the XML Schema in
the respective RDFS-statement of the class, I may use 'onto:A
someProperty rdf:resource="http://.../a_schema.xsd".' in the statement.
I would need an appropriate property. Have somebody any tip?

freundliche Gruesse / best regards
Dipl.-Ing. Kianoush Eshaghi     T +43 1 74040-652
METADAT - The Architect for Knowledge Networks