Authority Records

A Handbook of Examples For Use in Authority Records Created By the NACO-Music Project by Michelle Koth provides guidance on fields 670, 667 and 675 in the MARC Authority format. Although done by the NACO-Music Project it's usefulness is not limited to music. This has been around since 1998, but I've only recently seen it. Maybe I though it was only for music.

"This handbook is a compilation of examples with explanations for creating citations for sources of information in the authority record. It does not encompass establishing the heading itself; only how to cite the sources in which information necessary to create the heading was found. The examples are not to be regarded as "rules." The fields that are affected are:

670: Source data found: includes information about the name or title represented in the 1XX field, including facts that contribute to the identification of the heading and that justify the choice of the form used as the 1XX heading and references to it.

667: Non-public general note: gives information of permanent value and general interest that is not necessarily taken from the item being cataloged.

675: Source data not found: lists consulted sources in which information about the 1XX heading might be expected to be found, but was not."--pref.