Definition and scope:

The 00X variable control fields contain the record control number and other kinds of control and coded information that are used in the processing of machine-readable classification records (MARC records).  Each control field is identified by a field tag in the Directory and contains either a single data element or a series of fixed-length data elements identified by relative character position.

Variable control fields contain neither indicator positions nor subfield codes.

Each data element in the fixed-length field 008 is positionally defined.  A more detailed explanation of positionally defined data elements can be found in 008 Fixed-Length Data Elements.

The codes NR or R below indicate whether a field can be repeated in a record.

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

001  Control Number  (NR)

003  Control Number Identifier  (NR)

005  Date and Time of Latest Transaction  (NR)

008  Fixed-Length Data Elements  (NR)

See also:

MARC 21 Format for Classification Data:  Contents