688 Application History Note

Field definition and scope:

Field 688 contains information that documents changes in the application of a 1XX heading. The field may contain such historical information as when a topical term or a geographic name became valid for subject purposes, earlier forms of the heading, and the period during which each earlier form was valid.

The National level record requirement for this field is Optional.

Field 688 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 688	Application History Note	O	R
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	Application history note	M	NR
$5	Institution to which field applies	A	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R

Input conventions:

Punctuation and Spacing

LC Guidelines:

688 Application History Note