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

$5

Institution to which field applies

A

R

$6

Linkage

A

NR

$8

Field link and sequence number

O

R

Input conventions:

Capitalization

Spacing

Order

Display constant

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]

LC Guidelines:

 050  Library of Congress Call Number

DCM Z1 Instructions:

 050  Library of Congress Call Number

Related MARC fields or documents:

646  Series Classification Practice

880  Alternate Graphic Representation

Cutter-Sanborn Three-Figure Author Table

Library of Congress Classification

LC Classification--Additions and Changes

MARC Code List for Organizations

Subject Cataloging Manual: Classification

Subject Cataloging Manual:  Shelflisting

Symbols and Interlibrary Loan Policies in Canada

See also:

0XX  Numbers and Codes

Variable Data Fields