cpp's description of a partyid... this will work for us in trp... ibelieve

[Rik Drummond <rvd2@worldnet.att.net>]

If the type attribute is present, then it provides a scope or namespace for
the content of the PartyId element.

If the type attribute is not present, the content of the PartyId element
MUST be a URI that conforms to [RFC2396]. It is RECOMMENDED that the value
of the type attribute be an URN that defines a namespace for the value of
the PartyId element. Typically, the URN would be registered as a well-known
directory of organization identifiers.

The following example illustrates two URI references.

  <PartyId type = "uriReference">urn:duns.com:duns:1234567890123</PartyId>
  <PartyId type = "uriReference">urn:www.example.com</PartyId>

The first example is the URN for the Party's DUNS number, assuming that Dun
and Bradstreet has registered an URN for DUNS numbers with the Internet
Assigned Numbers Authority. The last field is the DUNS number of the
organization.

The second example shows an arbitrary URN.  This might be a URN that the
Party has registered with the Internet Assigned Numbers Authority (IANA) to
identify itself directly.