> From: Rebecca S. Guenther [mailto:[log in to unmask]]
> Sent: 23 June, 2004 09:50
> Subject: Re: [MODS] Fwd: [MODS] MADS: XML schema for authorities (fwd)
> The below concerning some of the MADS attributes was
> forwarded to me from another list. I am sending this response
> [problem definition deleted]
> entries. Also, we add new values to these regularly, so
> wouldn't want to have to maintain a specified list in the
> schema. Couldn't we just use a URI to reference these lists of values?
Over a year ago, I pointed out that MODS, and now MADS, should not
use hard coded values in the XML schema, but instead should use
URI's to define these types of values. By using URI's you make
the schema more flexible. Other non-library communities can use
the MODS/MADS schema with their own code lists, rather than
extending the schema or worst creating yet another metadata
format. I would, again, like to encourage the use of URI's for
code lists in MODS/MADS.
As a side note, MODS/MADS could use info URI's  for these code
lists. In our Terminology Services project  we make use of
info URI's for identifying Knowledge Organization Schemes (KOS).
Rather than invent another code list, our info URI registry
application  (pending approval) specifies that a code be
selected from the MARC code lists for term sources  or the
MARC code lists for classification sources .
A similar approach could be taken by MODS/MADS by applying to
the info URI registrar for specific authorities related to
MODS/MADS. Logically, the requested authorities might be MODS
and MADS. Where the info URI's might look like:
where <list> is the name of the code list and <code> is a value
from that code list. The <list> and <code> values may need to
be quoted with a percent followed by hex digits, depending upon
whether the characters they use are restricted characters for
Andrew Houghton, OCLC Online Computer Library Center, Inc.