686 Relationship to Source Note

Field definition and scope:

Field 686 contains information about the relationship of a number to the source edition when the number is different from the standard number for the same topic in the primary source edition. This field is used for numbers based on a source other than the primary source, expansions, implemented options, and adaptations. The information in this field is intended primarily for computer processing or to guide classifiers and is often not written in a form adequate for public user display.

Field 686 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 686	Relationship to Source Note	R
Indicator:
First	Type of relationship
0	Number from other source edition
1	Expansion
2	Option
3	Adaptation, other

Second	Undefined; contains a blank

Subfield code:
$a	Number in edition described in field 084 - single number or beginning number of span	R
$b	Number in primary source edition - single number or beginning number of span	R
$c	Ending number of span	R
$i	Explanatory note	R
$o	Number where instructions are found - single number or beginning number of span	R
$t	Topic	R
$y	Table sequence number for internal subarrangement or add table	R
$z	Table identification	R
$2	Edition identifier	R
$5	Institution to which field applies	R
$6	Linkage	NR
$8	Field link and sequence number	NR

See: Examples for this field.

Scheme-specific conventions:

Dewey Decimal Classification

Content designator history:

Subfield $y - Table sequence number for internal subarrangement or add table [new, 2008]