Thanks, Ross. For SRU, this is an opportune time to reconcile these 
differences.  Opportune, because we are approaching standardization of 
SRU/CQL within OASIS, and there will be a number of areas that need to 
change.

Some observations.

1. the 'ofi' namespace of 'info' has the advantage that the name, "ofi", 
isn't necessarily tied to a community or application (I suppose one could 
claim that  the acronym "ofi" means "openURL <something starting with 'f'> 
for Identifiers"  but it doesn't say so anywhere that I can find.)  However, 
the namespace itself (if not the name) is tied to OpenURL.  "Namespace of 
Registry Identifiers used by the NISO OpenURL Framework Registry".  That 
seems like a simple problem to fix.  (Changing  that title would not cause 
any technical problems. )

2. In contrast,  with the srw namespace,  the actual name is "srw". So at 
least in name, it is tied to an application.

3. On the other side, the srw namespace has the distinct advantage of 
built-in extensibility.  For the URI: info:srw/schema/1/onix-v2.0,  the "1" 
is an authority.   There are (currently) 15 such authorities, they are 
listed in the (second) table at 
http://www.loc.gov/standards/sru/resources/infoURI.html

Authority "1"  is the SRU maintenance agency, and the objects registered 
under that authority are, more-or-less, "public". But objects can be defined 
under the other authorities with no registration process required.

4.  ofi does not offer this sort of extensibility.


So, if we were going to unify these two systems (and I can't speak for the 
SRU community and commit to doing so yet) the extensibility offered by the 
srw approach would be an absolute requirement.   If it could somehow be 
built in to ofi,  then I would not be opposed to migrating the srw 
identifiers.   Another approach would be to register  an entirely  new 
'info:' URI namespace and migrating all of these identifiers to the new 
namespace.

--Ray


----- Original Message ----- 
From: "Ross Singer" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, April 30, 2009 2:59 PM
Subject: One Data Format Identifier (and Registry) to Rule Them All


> Hello everybody.  I apologize for the crossposting, but this is an
> area that could (potentially) affect every one of these groups.  I
> realize that not everybody will be able to respond to all lists,
> but...
>
> First of all, some back story (Code4Lib subscribers can probably skip 
> ahead):
>
> Jangle [1] requires URIs to explicitly declare the format of the data
> it is transporting (binary marc, marcxml, vcard, DLF
> simpleAvailability, MODS, EAD, etc.).  In the past, it has used it's
> own URI structure for this (http://jangle.org/vocab/formats#...) but
> this was always been with the intention of moving out of the
> jangle.org into a more "generic" space so it could be used by other
> initiatives.
>
> This same concept came up in UnAPI [2] (I think this thread:
> http://old.onebiglibrary.net/yale/cipolo/gcs-pcs-list/2006-March/thread.html#682
> discusses it a bit - there is a reference there that it maybe had come
> up before) although was rejected ultimately in favor of an (optional)
> approach more in line with how OAI-PMH disambiguates metadata formats.
> That being said, this page used to try to set sort of convention
> around the UnAPI formats:
> http://unapi.stikipad.com/unapi/show/existing+formats
> But it's now just a squatter page.
>
> Jakob Voss pointed out that SRU has a schema registry and that it
> would make sense to coordinate with this rather than mint new URIs for
> things that have already been defined there:
> http://www.loc.gov/standards/sru/resources/schemas.html
>
> This, of course, made a lot of sense.  It also made me realize that
> OpenURL *also* has a registry of metadata formats:
> http://alcme.oclc.org/openurl/servlet/OAIHandler?verb=ListRecords&metadataPrefix=oai_dc&set=Core:Metadata+Formats
>
> The problem here is that OpenURL and SRW are using different info URIs
> to describe the same things:
>
> info:srw/schema/1/marcxml-v1.1
>
> info:ofi/fmt:xml:xsd:MARC21
>
> or
>
> info:srw/schema/1/onix-v2.0
>
> info:ofi/fmt:xml:xsd:onix
>
> The latter technically isn't the same thing since the OpenURL one
> claims it's an identifier for ONIX 2.1, but if I wasn't sending this
> email now, eventually SRU would have registered
> info:srw/schema/1/onix-v2.1
>
> There are several other examples, as well (MODS, ISO20775, etc.) and
> it's not a stretch to envision more in the future.
>
> So there are a couple of questions here.
>
> First, and most importantly, how do we reconcile these different
> identifiers for the same thing?  Can we come up with some agreement on
> which ones we should really use?
>
> Secondly, and this gets to the reason why any of this was brought up
> in the first place, how can we coordinate these identifiers more
> effectively and efficiently to reuse among various specs and
> protocols, but not:
> 1) be tied to a particular community
> 2) require some laborious and lengthy submission and review process to
> just say "hey, here's my FOAF available via UnAPI"
> 3) be so lax that it throws all hope of authority out the window
> ?
>
> I would expect the various communities to still maintain their own
> registries of "approved" data formats (well, OpenURL and SRU, anyway
> -- it's not as appropriate to UnAPI or Jangle).
>
> Does something like this interest any of you?  Is there value in such
> an initiative?
>
> Thanks,
> -Ross.