684 Auxiliary Instruction Note

Field definition and scope:

Field 684 contains a note which gives information from, or reference to, a section of a classifier's manual or other documentation. An auxiliary instruction note provides advice for classifying in difficult areas, and describes policies and practices that may accompany a classification schedule.

Examples of auxiliary instructions may be found in the Dewey Decimal Classification manual or other documentation intended to be used with a classification schedule. A separate 684 note is used when different types of notes are recorded, identified by the first indicator.

The information in this field is primarily intended to guide classifiers and is often not written in a form adequate for public user display.

Field 684 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 684	Auxiliary Instruction Note	R
Indicator:
First	Type of note
0	Source entry
1	Textual note
2	Reference note

Second	Undefined; contains a blank

Subfield code:
$a	Classification number - single number or beginning number of span	R
$c	Classification number - ending number of span	R
$i	Explanatory text	R
$j	Caption	NR
$y	Table sequence number for internal subarrangement or add table	R
$z	Table identification	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]