Hi, On Feb 11, 2010, at 4:51 PM, Walls, Ian wrote:
Both headings are stored in the USMARC 650 field. They use different second indicators to delineate source; LCSH is 0, MeSH is 2. In the MARC, this is the only way to tell which source a header in a bibliographic record comes from.
To mention a wrinkle in this - if the second indicator of the 650 is 7, the thesaurus is identified in the subfield $2 of the heading.
I would think I should create a new Authority Type for MeSH, but it’s MARC framework would be exactly the same as TOPIC_TERM, since the MARC frameworks do not currently factor in indicators in any way. Looking at the code bulkauthimport.pl, which looks at whether the incoming record has certain MARC fields (100 for PERSO_NAME, 150 for TOPIC_TERM, etc.), the mappings are hardcoded. That is, there is no way for me to specify that these incoming MARC authorities, which have 150 fields in them, are MeSH and not TOPIC_TERM.
The thesaurus type is orthogonal to the authority record type, so I suggest not creating a whole new framework just for MeSH headings if we can avoid it. Working on including the thesaurus in the bib headings indexes would be an excellent project for 3.4. When I did the config work for the DOM indexing of MARC21 authority records, I indexed the thesaurus - see etc/zebradb/marc_defs/marc21/authorities/authority-koha-indexdefs.xml. Regards, Galen -- Galen Charlton VP, Data Services Equinox Software, Inc. / The Evergreen Experts email: gmc@esilibrary.com direct: +1 352-215-7548 skype: gmcharlt web: http://www.esilibrary.com/