010 Library of Congress Control Number

Field definition and scope:

Field 010 contains a unique number that has been assigned to a bibliographic record by the Library of Congress. The control number for MARC records distributed by LC is an LC control number (LCCN). Field 010 may also contain a canceled or invalid control number of a previously-distributed record or one erroneously recorded on the item being described.

The LCCN is carried in field 001 (Control Number) in records distributed by LC's Cataloging Distribution Service and in field 010$a. An organization using LC records may remove the LC control number from field 001 and use field 001 for its own system control number.

The National level record requirement for this field is Mandatory if applicable.

Field 010 is NOT repeatable.

Guidelines for applying content designators:

For indicator and subfield code definitions and examples, National-level (NLR) and Minimal-level (MLR) record requirements, and designator repeatability, see table below:

Position	Description	NLR	MLR	Repeatability
Field 010	Library of Congress Control Number	A	A	NR
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	LC control number	A	A	NR
$b	NUCMC control number	A	A	R
$z	Canceled/invalid LC control number	A	A	R
$8	Field link and sequence number	O	O	R

Structure:

LC Control Number Structure

Input conventions:

Classes of LCCNs

Agency-assigned field

Punctuation

Capitalization