Field definition and scope:

Field 010 contains a unique number assigned to a record by the Library of Congress.  The LC control number is carried in field 001 (Control Number) in records distributed by LC's Cataloging Distribution Service.  It may also be carried in field 010$a.

An LC record may contain field 010 with a canceled or invalid control number of a previously-distributed record.  A record may be canceled because it is a duplicate and represents the same classification data represented by another record.  The structure of the canceled or invalid control number is the same as that used by LC in field 001.  Field 010 may or may not contain a subfield $a with the valid control number from the 001 field.

Field 010 is NOT repeatable.

Guidelines for applying content designators:

For indicator and subfield code definitions and examples, and designator repeatability, see table below:




Field 010

Library of Congress Control Number






Undefined; contains a blank



Undefined; contains a blank





Subfield code:




LC control number



Canceled/invalid LC control number



Field link and sequence number



LC Control Number Structure

Input conventions:

Agency Information - Field 010 is an agency-assigned field; it may be used only for an LC control number.

Punctuation - Field 010 does not end in a mark of punctuation.

Capitalization - Prefixes are always input as lowercase alphabetic characters.

Related MARC field or document:

001  Control Number

See also:

0XX  Numbers and Codes

Variable Data Fields