self identifying in RDF Schema

Folks,
 
How can we provide information about the URI of the RDF Schema that we are
working with?. the intent is to identify the RDF Schema we obtained somehow(
got it on a floppy disk, sent to me a network packet etc...etc...). 
 
The problem is we can not create a new resource, as the schema is already
existing. We have to use rdf:about and provide the URI of the schema and
then use rdfs:isDefinedBy to specify the URI. But, this doesn't tell us if
the URI pointed to by the resource is same as the RDF Schema we are
processing.
 
Alternatively we can enforce that every RDF Schema document we process has a
special resource named 'XYZ' whose isDefinedBy property value would point to
the URI of the Schema document. But, this solution is a interoperability
nightmare. 
 
There has to be a more elegant, simple way to do this( something like
targetNamespace ?). 
 
What is the suggested way to identify a RDF Schema itself in the document?.
 
Thoughts?.
 
Sateesh