654 Subject Added Entry - Faceted Topical Terms

Field definition and scope:

Field 654 contains a topical subject constructed from a faceted vocabulary. For each term found in the field, an identification is given as to the facet/hierarchy in the thesaurus from which the term came. In addition, identification is given as to which term is the focus term of the expression. A field may contain more than one expression.

Field 654 is repeatable.

Guidelines for applying content designators:

For indicator and subfield code definitions and examples, and designator repeatability, see table below:

Position	Description	Repeatability
Field 654	Subject Added Entry - Faceted Topical Terms	R
Indicator:
First	Level of subject
#	No information provided
0	No level specified
1	Primary
2	Secondary

Second	Undefined; contains a blank

Subfield code:
$a	Focus term	NR
$b	Non-focus term	R
$c	Facet/hierarchy designation	R
$v	Form subdivision	R
$y	Chronological subdivision	R
$z	Geographic subdivision	R
$0	Authority record control number or standard number	R
$1	Real World Object URI	R
$2	Source of heading or term	NR
$3	Materials specified	NR
$6	Linkage	NR
$8	Field link and sequence number	R

Input conventions:

Punctuation

Display constant

Content designator history:

Subfield $0 - Authority record control number [new, 2007]

Subfield $0 - Authority record control number [redefined, 2010]

Subfield $1 - Real World Object URI [new, 2017]