050 Library of Congress Call Number

Field definition and scope:

Field 050 contains a Library of Congress (LC) call and/or class number for a series when all or part of the series is classified as a collected set or with the main series (646 Series Classification Practice, subfield $a, code c or m). 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.

Field 050 may also contain the volumes/dates to which the number applies. Varying numbers for different ranges of volumes/dates within a series or different copies or sets are contained in separate 050 fields.

The source of the classification number is Library of Congress Classification and the 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 050 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 050	Library of Congress Call Number	O	R
Indicator:
First	Undefined; contains a blank	M

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

Subfield code:
$a	Classification number	M	NR
$b	Item number	A	NR
$d	Volumes/dates to which call number applies	current - O earlier - M	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:

Content designator history:

Second Indicator - Source of Call Number [defined]: The second indicator position was defined in 1982. Prior to that change, 050 was an agency-assigned field and contained only call 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:

050 Library of Congress Call Number

DCM Z1 Instructions:

050 Library of Congress Call Number