> From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of
> Ray Denenberg, Library of Congress
> Sent: Wednesday, April 01, 2009 12:55 PM
> To: [log in to unmask]
> Subject: Re: [CODE4LIB] resolution and identification
> A concrete example.
> The MODS schema, version 3.3, has an info identifier, for SRU purposes:
> So in an SRU request you can say"
Yes, but you can use any token for a recordSchema so long as everyone
agrees that the token represents the schema for MODS 3.3. You could
have just as well used an HTTP URI for that parameter in SRU which
is what I typically do for things like SKOS.
> Now in contrast, the schema is at
This could have been used in place of the info URI for the SRU. This
URI is a Web Document and probably is the definitive URI for version
3.3 of the MODS XML schema.
> And it's also at:
This is a URI alias. The Architecure of the Web warns us not to create
URI aliases, but HTTP allows use to do two things with this URI: 1)
redirect it to the correct URI or use the Content-Location header to
indicate that it is a URI alias. Neither of which is done by the LC
> And also:
These are not the same URI as previous URIs. These URIs is to the latest
MODS XML schema document. It's semantics are that of the "current"
version of the schema. One of these is another URI alias that has the
same issues as I previously stated.
This URI is not the same as URI as previous URIs. This URI is to the
latest MODS version 3 XML schema document. It's semantics are that of
the "current" version 3 of the schema.
> So there you have five http "identifiers" for the schema.
At this point in time all five of these HTTP URIs my dereference to the
Web Document, but overtime the latter three will not represent version 3.3
of the MODS XML schema. The first URI is most likely the definitive URI
for version 3.3 of the MODS XML schema.
Organization need to have a clear understanding of what they are minting