The MARC 21 Format for Authority Data is designed to be a carrier for information concerning the authorized forms of names, subjects, and subject subdivisions to be used in constructing access points in MARC records, the forms of these names, subjects, and subject subdivisions that should be used as references to the authorized forms, and the interrelationships among these forms.

A name may be used as a main, added, series, or subject access entry.  The term name refers to:

 Personal names (X00)

 Names of jurisdictions (X51)

 Corporate names (X10)

 Uniform titles (X30)

 Meeting names (X11)

 Name/title combinations

A subject may be used only as a subject access entry.  The term subject refers to:

 Topical terms (X50)

 Topical terms, geographic names, and genre/form terms with subject subdivisions

 Geographic names (X51)

 Genre/form terms (X55)

 Chronological terms (X48)

 Names with subject subdivisions

 Uniform titles with subject subdivisions (X30)

A subject subdivision may be used with a name or subject lead element in an extended subject access entry.  It may not be used as the lead element in a main, added, series, or subject access entry.  The term subject subdivision refers to:

 General subdivision terms (X80)

 Geographic subdivision names (X81)

 Chronological subdivision terms (X82)

 Form subdivision terms (X85)

The MARC 21 Format for Authority Data also provides for information concerning the authorized forms of node labels.  A node label is not assigned to documents as an indexing term.

See also:

Authority Data Format:  Introduction