Hi Jan,

> I am working on a MARC to MODS mapping for one of our journal files. Each 
> journal record may contain holdings information from the 852 and from 
> local holdings fields as below:
> 
> ISI Bulletin
> 
> Location: British Library
> Sub-collection: DSC
> Shelfmark: 4582.950000
> Holdings: Vol.1, 1949- 39(2), 1987
> 
> Location: British Library
> Sub-collection: STI
> Shelfmark: (P)BY40-E(1)
> Holdings: Vol.5, 1953-8, 1956; 1962-39(3), 1987
> 
> Is my only (or best) way to handle this in MODS to use an <extension> 
> holdings schema? I have some concerns about interoperability issues if I 
> use the <extension> element. For example, I know that in the UK, another 
> consortium is developing its own local holdings extensions while the 
> example in the MODS Guidelines is for the Z39.50 XML Holdings schema 
> (which may be overly complex for these simple holdings summaries anyway). 
> So I've been looking at using <location> and <physicalLocation> as 
> elements for Location/Sub-collection and Shelfmark but am having problems 
> linking the relevant holdings to the right location using 
> <physicalDescription> <extent>.

We have the same issue. What we are currently doing (though it's
not quite yet too late to change) is using our own schema in the
extension element. A simple holdings statement goes something like this:

  <cpc:lhi libCode="Abc" libName="Aybesee" crn="01234567890">
   <cpc:localHold>
    <cpc:itemLoc>
     <cpc:branchLoc code="STRM">Store room</cpc:branchLoc>
     <cpc:classmark>HN740.Z9.S6 M54</cpc:classmark>
    </cpc:itemLoc>
   </cpc:localHold>
   <cpc:localNote>Some local note would go here</cpc:localNote>
  </cpc:lhi>

Which satisfies our basic requirements. The attributes in the
first line contain stuff very specific to CURL/Copac.
There are other tags (not shown above) for enum & chrons and
for textual holdings statements.

It would be nice to be interoperable (especially as we have
your records on Copac.) I'm afraid the Z39.50 XML Holdings
Schema had passed me by. Do many people use it? (Having had
a quick look at it, it seems overly complex for what we need.)

 > 1. Are my concerns about interoperability and the use of the
 > <extension> element too great?

I wish I knew the answer to that.

Regards,

Ashley.
-- 
Ashley Sanders [log in to unmask]
Copac http://copac.ac.uk -- A MIMAS service funded by JISC