Local control number and document Id

Issue raised by: David Loy 30 May 1996

Synopsis: What is the difference between tagSet-M tag 14 (local control number) and tagSet-G tag 5 (documentId)?
Semantically these correspond respectively to the bib-1 attributes local number (12) and docId (1032). The first has bibliographic overtones: it identifies a record in a local system, as long as that system is not LC, Deutch Bibliotethek, Bibliotheque Nationale Francais, or BL. So docId was added, as more generic. Note that for the Z39.50r url, docId is used, not local number. The url definition says:
The docid is placed into a type-1 query, as the single term, in the general format (tag 45), using the Bib-1 attribute set, with a Use attribute value of docid, and a structure attribute of Urx. The docid string is server-defined and completely opaque to the client.

Status: Approved (10/96)
Library of Congress
Library of Congress Help Desk (10/18/96)