Coding of Subject Headings in the Union Catalogue

The second indicator value signifies the subject thesaurus in the following fields: 600, 610, 611, 630, 650, 651, 655. Most of our subject headings will be coded in 650 fields with second indicator value 0, for LC subject headings. Other possibilities are given in the table below.

Subject heading system6XX 2nd indicatorUsed in our catalogueAuthorities
LCSH0In original and derived recordsSys/Thes (008/11) value 'a'
Children's headings1In some derived records only; no need to deleteSys/Thes (008/11) value 'b' Records no longer in our authority file
MeSH (NLM medical headings)2In derived records for Gerstein, Mount Sinai, etc.; do not delete Sys/Thes (008/11) value 'c'
No records in our authority file
Local4Do not usen/a
Canadian subject headings5Use only those where an authority record has been created Sys/Thes (008/11) value 'k
Répertoire de vedettes-matière6Do not use; delete from derived records Sys/Thes (008/11) value 'v'
No records in our authority file
Other source of subject term7Use with 655 field when coding genre termsn/a

Here are some reminders about our subject heading practice based on the CDC Subject Heading Guidelines originally issued in September 1995:

  • Do not copy subject authority records from LC into our authority file. LCSH records are loaded weekly into our system.
  • Do not create CANMARC subject authority records. Notify the CDC if you think a CANMARC heading is required.
  • Delete 653 fields if the access they provide is too broad to be useful, provided there is at least one other adequate subject heading in the record.
  • For locally-assigned subject headings, use the 690 field. The indicators are blank and only subfield |a is defined.

7 June 2005