072 Subject Category Code

Field definition and scope:

Field 072 contains a code for the subject category that is associated with the item. Field 072 is repeated for multiple subject category codes.

The National level record requirement for this field is Optional.

Field 072 is 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 072	Subject Category Code	O	O	R
Indicator:
First	Undefined; contains a blank	M

Second	Code source	M
0	National Agricultural Library subject category code list	A
7	Source specified in subfield $2	A

Subfield code:
$a	Subject category code	M	O	NR
$x	Subject category code subdivision	A	O	R
$2	Source	A	O	NR
$6	Linkage	A	O	NR
$8	Field link and sequence number	O	O	R

Content designator history:

Second Indicator - Code source (BK SE): The definition of the second indicator position in 1981 broadened the scope of this field to include codes taken from any subject category code list. Prior to that time, the field was used only for National Agricultural Library codes and the second indicator contained a # (blank) meaning undefined.