520 Summary, Etc.

Field definition and scope:

Field 520 contains unformatted information about the scope and general contents of the described materials. This could be a summary, abstract, annotation, review, or only a phrase describing the material.

The level of detail appropriate in a summary may vary depending on the audience for a particular product. When a distinction between levels of detail is required, a brief summary is given in subfield $a and a fuller annotation is given in subfield $b.

The text is sometimes displayed and/or printed with an introductory term that is generated as a display constant based on the first indicator value.

The National level record requirement for this field is Optional.

Field 520 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 520	Summary, Etc.	O	O	R
Indicator:
First	Display constant controller	M
#	Summary	A
0	Subject	A
1	Review	A
2	Scope and content	A
3	Abstract	A
4	Content advice	A
8	No display constant generated	A

Second	Undefined; contains a blank	M

Subfield code:
$a	Summary, etc.	M	O	NR
$b	Expansion of summary note	O	O	NR
$c	Assigning source	O	O	NR
$u	Uniform Resource Identifier	O	O	R
$2	Source	O	O	NR
$3	Materials specified	O	O	NR
$6	Linkage	A	O	NR
$8	Field link and sequence number	O	O	R

Input conventions:

Punctuation

Display constants

Content designator history:

First indicator - Display constant controller

Value 4 - Content advice [new, 2007]

Subfield $c - Assigning source [new, 2007]

Subfield $u - Uniform Resource Identifier [new, 2000]

Subfield $z - Source of note information (BK AM CF SE) [obsolete]: Subfield $z was made obsolete in 1990. Source information is included as part of the summary note in subfield $a or the expansion of the summary note in subfield $b.

Subfield $2 - Source [new, 2007]