042 Authentication Code

Field definition and scope:

Field 042 contains one or more authentication codes indicating that the record, existing in a national database, has been reviewed in a specific way. Field 042 is an agency-assigned data element. It is used for authentication codes associated with specifically designated authenticating agencies.

A listing of authentication codes for field 042 is available at: Value Lists for Codes and Controlled Vocabularies (MARC Authentication Action Code List).

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

Field 042 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 042	Authentication Code	A	A	NR
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	Authentication code	M	M	R

Input conventions:

Capitalization

Order of codes

Content designator history:

Subfield $a - Authentication code

dc - Dublin Core [new, 2000]

dlr - Digital Library Repository [new, 2003]

issnuk - ISSN UK [new, 2003]

nst - New Serial Titles (SE) [obsolete, 1984]

sanb - South African National Bibliography Project [new, 2000]

xissnuk - ISSN UK does not consider item a continuing resource [new, 2003]