053 LC Classification Number

Field definition and scope:

Field 053 contains a single LC classification number or a number span associated with a 1XX heading in an established heading record or a subdivision record. The classification number(s) may be qualified by a descriptive term when the heading is represented in more than one place in the LC classification schedules. Each classification number or number span associated with a heading is contained in a separate 053 field. The second indicator values distinguish between content actually assigned by the Library of Congress and content assigned by an organization other than LC. The organization is identified in subfield $5.

The source of the classification number is Library of Congress Classification schedules and LC Classification--Additions and Changes that are maintained by the Library of Congress. Organizations may conform to Library of Congress practice by applying Subject Cataloging Manual: Classification conventions.

The National level record requirement for this field is Optional.

Field 053 is repeatable.

Guidelines for applying content designators:

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

Position	Description	NLR	Repeatability
Field 053	LC Classification Number	O	R
Indicator:
First	Undefined; contains a blank	M

Second	Source of classification number	M
0	Assigned by LC	A
4	Assigned by agency other than LC	A

Subfield code:
$a	Classification number element - single number or beginning number of span	M	NR
$b	Classification number element - ending number of span	A	NR
$c	Explanatory term	A	NR
$0	Authority record control number or standard number		R
$1	Real World Object URI		R
$5	Institution to which field applies	A	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R

Input conventions:

Capitalization

Spacing

Display constants

Content designator history:

Second Indicator - Source of Classification Number [defined, 1995]: Prior to 1995, field 053 was an agency-assigned field and contained only classification numbers assigned by the Library of Congress. LC records created before the definition of this indicator may contain a # (blank) meaning undefined in this position.

Subfield $0 - Authority record control number or standard number [new, 2017]

Subfield $1 - Real World Object URI [new, 2017]

LC Guidelines:

053 LC Classification Number

DCM Z1 Instructions:

053 LC Classification Number