Definition and scope:

The variable data fields include fields 0XX to 9XX.  They may vary in length and may contain any text or other data needed to describe an individual bibliographic item or other type of record.  They are grouped into blocks according to the first character of the tag, which, with some exceptions, identifies the function of the data within the record.  The type of information in the field is identified by the remainder of the tag.

Within the 1XX, 4XX, 6XX, 7XX, and 8XX blocks, certain parallels of content designation are usually preserved.  The following meanings, with some exceptions, are given to the final two characters of the tag of fields:

X00  Personal names

X10  Corporate names

X11  Meeting names

X30  Uniform titles

X40  Bibliographic titles

X50  Topical terms

X51  Geographic names

Each field is identified by a field tag in the Directory.  Within variable data fields, two kinds of content designation are used:  two indicator positions stored at the beginning of each field, and a two-character subfield code preceding each data element within the field.

 Heading Fields:  Indicators, subfield codes, and input conventions for all the fields which include headings follow similar patterns.  For detailed information, select:  Headings:  X00-X30 Fields.

For information on a specific variable data field, select a topic:

(Shortcut:  For information on a particular field, use the Tag Lists to search by tag, subject area, or alphabetically.)

Tag range:

Field description:


Numbers and Codes


Main Entry Fields


Title and Title-Related Fields


Edition, Imprint, Etc. Fields


Physical Description, Etc. Fields


Series Statement Fields


Note Fields


Subject Access Fields


Added Entry Fields


Linking Entry Fields


Series Added Entry Fields


Holdings, Alternate Graphics, Etc.


Locally-Defined Fields

See also:

Variable Control Fields  (00X)

MARC 21 Format for Bibliographic Data:  Contents