Object and Extension Identification Issue?

["Hollenbeck, Scott" <shollenbeck@verisign.com>]

While testing one of the schema changes that'll be done in the next version
of EPP I encountered something that may or may not be an issue for
implementers.  I'd like to ask if this is a problem, and if it is I can get
a fix into the next drafts.

Objects and extensions are described in a <greeting> and <login> command
like this:

<contact:svc
  xmlns:contact="urn:ietf:params:xml:ns:contact-1.0"
  xsi:schemaLocation="urn:ietf:params:xml:ns:contact-1.0
  contact-1.0.xsd"/>

The issue is that if the receiving end doesn't happen to have a copy of the
schema file on it's search path, at least one parser (Xerces-J) will throw
an exception because it can't find the file.  It's certainly likely that not
all clients will understand all of the objects or extensions supported by a
server, and the server may receive a <login> request containing a <svc>
element that it won't understand.

So, is it a problem for implementers if the parser chokes when it can't find
a schema file?  If so, I can change things so that the <greeting> and
<login> describe services using the appropriate namespace URIs, like this:

<objURI>urn:ietf:params:xml:ns:contact-1.0</objURI>

Discussion, please?

<Scott/>