Thanks very much for the clarifications, Ray.
I personally would find it clearer, cleaner, safer and potentially more
useful if MODS maintained any generic schema urls at the integral
version level, and if such generic URLS resolved to the most recent,
backwards compatible version of the MODS schema within an integral
version series of MODS schemas. In other words, I think it would be
better if the most recent version of the mods schema representing the
"http://www.loc.gov/mods/v3" target namespace were available at
"http://www.loc.gov/standards/mods/v3/mods.xsd". (Offhand I have to
wonder how mods users are employing the non integral version specific,
generic mods URL, although I suppose it does provide a shorthand way of
getting to the most recent schema in an informal context.)
Such a practice would also align with the way the METS Board intends to
manage the METS schema generic URL--or at least intended the last time
we discussed the matter. However, with METS I think we made a very
short-sighted mistake by not including a version 1 designation in either
the target namespace URI (http://www.loc.gov/METS/) or the generic URL
(http://www.loc.gov/standards/mets/mets.xsd) associated with version 1
of the schema. We are still in Version 1 of METS, but when and if we
move to a version 2 series of the schema, we will clearly need to add a
version designation to the target namespace URI for version 2
(http://www.loc.gov/METS/v2) as well as create a generic, version 2 URL
(http://www.loc.gov/standards/mets/v2/mets.xsd) that will always yield
the current METS schema in the version 2 series.
Ray Denenberg, Library of Congress wrote:
> I'll try to address all the points made in this thread.
> - The most current version of MODS will always be maintainted at:
> and in addition will be maintained at a version-specific URL. Since
> 3.3 is the most current version, the schemas at the two URLs
> http://www.loc.gov/standards/mods/mods.xsd, and
> http://www.loc.gov/standards/mods/v3/mods-3-3.xsd are identical
> (though at different locations).
> - "Can users count on the more generic URL always pointing to the
> most recent version of the MODS schema that is backwards compatible
> through version 3.1?" No. Once we go to version 4.0, then the 4.0
> schema will be at http://www.loc.gov/standards/mods/mods.xsd.
> We could maintain the most recent 3.x version at
> http://www.loc.gov/standards/mods/v3/mods.xsd if that would be
> useful. So let's say we have a version 3.4, then 3.5, and then 4.0.
> Then the version 3.5 schema would remain permanenty at
> http://www.loc.gov/standards/mods/v3/mods.xsd . Note, we have no
> plans to do this, but we could if there was a demand for it.
> - "(I believe that there is a break in compatibility between
> version 3.0 and 3.1)." No, there was a break in compatibility from
> version 2 to version 3.0, but not from version 3.0 to version 3.1.
> - "I am asking this because of its implications for how the
> schemaLocation in mods instances should be set up." schemaLocation
> should never be set to http://www.loc.gov/standards/mods/mods.xsd.
> If you create a MODS record with the intention that it conforms to
> version 3.3 (but not necessarily to any higher version), then
> schemaLocation should be
> - On the MODS namespace URI: when we go to version 4, the namespace
> URI will change. It will remain the same for all future 3.x versions.
> I've tried to capture all the questions in the thread, let me know if
> I missed any.
> From: "Rick Beaubien" <[log in to unmask]>
>> The current version of MODS is available both through a version
>> specific URL (http://www.loc.gov/standards/mods/v3/mods-3-3.xsd) as
>> well as a more generic URL
>> (http://www.loc.gov/standards/mods/mods.xsd). Can users count on the
>> more generic URL always pointing to the most recent version of the
>> MODS schema that is backwards compatible through version 3.1? (I
>> believe that there is a break in compatibility between version 3.0
>> and 3.1). Or, to phrase the question a little differently, if a new
>> version of the MODS schema was produced that was not backwards
>> compatible with versions 3.1-3.3, would it replace the 3.3 schema
>> that is now available via the generic URL
>> http://www.loc.gov/standards/mods/mods.xsd? I am asking this because
>> of its implications for how the schemaLocation in mods instances
>> should be set up.
>> Rick Beaubien
>> Rick Beaubien
>> Software Engineer, Research and Development
>> U.C. Berkeley Library
>> Contact information:
>> 88 Herrada Rd
>> Santa Fe, NM 87508
Software Engineer, Research and Development
U.C. Berkeley Library
88 Herrada Rd
Santa Fe, NM 87508