> From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of
> Eric Lease Morgan
> Sent: Wednesday, June 25, 2008 3:21 PM
> To: [log in to unmask]
> Subject: [CODE4LIB] alpha characters used for field names
> 
> Are alpha characters used for field names valid in MARC records?
> 
> When we do dumps of MARC records our ILS often dumps them with FMT and
> CAT field names. So not only do I have glorious 246 fields and 100
> fields but I also have CAT fields and FMT fields. Are these features
> of my ILS -- extensions of the standard -- or really a part of MARC?
> Moreover, does something like Marc4J or MARC::Batch and friends deal
> with these alpha field names correctly?

ISO 2709 allows tags to consists of three ASCII numeric characters or ASCII alphabetic characters (uppercase or lowercase, but not both) [1].  MARC-21 only uses numeric tags.  However, when I was OCLC representative for the MARC-XML standard, the pattern that it uses for tags is:

      <xsd:pattern value="(0([1-9A-Z][0-9A-Z])|0([1-9a-z][0-9a-z]))|(([1-9A-Z][0-9A-Z]{2})|([1-9a-z][0-9a-z]{2}))"/>

this change was a request from the RLG representatives who had MARC records in their system that contained alpha-numeric tags.


Andy.


[1] <http://www.loc.gov/marc/specifications/specrecstruc.html#direct>