553 Valid Number Tracing (VDF)

553 Valid Number Tracing (R) (Variable Data Field)

Field definition and scope: This field contains a tracing from one valid classification number to another. It is used in a record for a valid or partially valid classification number (008/08 Classification validity , code a, b or c). If the classification number in the tracing is valid for some topics but invalid for others, this field is used, and the topics that refer to another number are specified in subfield $t (Topic).

The content designators used in the classification number and caption portions of field 553 are the same as those defined for fields 153 (Classification Number) and 453 (Invalid Number Tracing) . Guidelines for applying these content designators, including indicators, scheme-specific conventions and input conventions, are given in the X53 Classification Numbers - General Information section.

Guidelines for applying tracing subfield codes, including scheme-specific conventions and input conventions, are given in the Tracings and References - General Information section.

Field 553 is repeatable .

Guidelines for applying Content Designators:

Indicators

First Source of classification number

0 Schedule

1 Table

Second Undefined; contains a blank (#)

Subfield Codes

$a Classification number element - Single number or beginning number of span (R)

$c Classification number element - Ending number of span (R)

$h Caption hierarchy (R)

$i Reference instruction phrase (NR)