646 Series Classification Practice (Authority)

646 Series Classification Practice (R) (Variable Data Field)

Field definition and scope:

Field 646 contains a one-character alphabetic code that indicates a specific organization's classification practice for a series named in the 1XX field of an established heading record for a series . The code specifies whether the volumes in the series are classified as a collection, with the main series, or separately. The field may also contain the volumes/dates and/or the institution/copy identification to which the classification practice applies.

Field 646 is not used to indicate that a series-like phrase is not classified.

Varying classification practices for different

ranges of volumes/dates within a series

copies or sets within the same organization

organizations

are contained in separate 646 fields.

The National level record requirement for this field is Optional.

Field 646 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 646	Series Classification Practice	O	R
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	Series classification practice	M	NR
$d	Volumes/dates to which classification practice applies	*current -* O earlier - M	NR
$5	Institution/copy to which field applies	M	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R