685 History Note (R) (Variable Data Field)
Field definition and scope: This field contains information about the history of the use and meaning of a classification number. The history information contained in this field refers to the number in field 153 (Classification Number) of the classification record unless a 453 (Invalid Number Tracing) or 553 (Valid Number Tracing) field contains code a (History reference, field 685 used) in control subfield $w/3 (History reference). If the tracing contains code a in subfield $w/3, the history reference refers to the number in that field. If there are two tracings in the record, both with code a in subfield $w/3, the number in subfield $a or $b identifies to which tracing the history note refers.
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 685 is repeatable .
Guidelines for applying Content Designators:
Indicators
8 Other
Second Type of history information
1 Formerly
8 Other
Subfield Codes
$a New number - Single number or beginning number of span (R)
$b Previous number - Single number or beginning number of span (R)
$c Classification number - Ending number of span (R)
$d Date of implementation of authoritative agency (NR)
$e Local implementation date (NR)
$f Title and publication date (NR)
$i Explanatory text (R)
$t Topic (R)
$y Table identification - Schedule (R)
$z Table identification - Table number (R)
$5 Institution to which field applies (R)
$8 Link and sequence number (NR)
Conventions: Dewey Decimal Classification (Scheme-Specific)
Related USMARC fields or documents:
084 Classification Schedule and Edition
353 Complex See Also Reference
763 Internal Subarrangement or Add Table Entry
USMARC Code List for Organizations
See also:
