553 Valid Number Tracing

Field definition and scope:

Field 553 contains a tracing for a cross reference from one valid classification number to another valid classification number. 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).

It is used in a record for a valid or partially valid classification number (008/08 Classification validity, code a, b or c). 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).

Field 553 is repeatable.

Guidelines for applying content designators:

Guidelines for applying these content designators, including indicators, scheme-specific conventions and input conventions, also are given in the X53 Classification Numbers - General Information section.

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

For indicator and subfield code definitions and examples, and designator repeatability, see table below:

Position	Description	Repeatability
Field 553	Valid Number Tracing	R
Indicator:
First	Source of classification number
0	Schedule
1	Table

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
$h	Caption hierarchy	R
$i	Reference instruction phrase	NR
$j	Caption	NR
$k	Summary number span caption hierarchy	R
$t	Topic	NR
$w	Control subfield	NR
	/0 - Special relationship
	a Previous classification number
	b New classification number
	i Reference instruction phrase in subfield $i
	j See reference
	k Class elsewhere reference
	l See also reference
	m Standard subdivisions do-not-use reference
	n Not applicable
	/1 - Hierarchical relationship
	g Number representing broader topic
	h Number representing narrower topic
	n Not applicable
	/2 - Reference display
	a Reference not displayed
	n Not applicable
	/3 - History reference
	a History reference, field 685 used
	n Not applicable
$y	Table sequence number for internal subarrangement or add table	R
$z	Table identification	R
$6	Linkage	NR
$8	Field link and sequence number	R

See: Examples for this field.

Input conventions:

Order of subfields

Invalid classification numbers

Number spans

Display of classification numbers and captions

Display constants for cross references

Scheme-specific conventions:

Library of Congress Classification

Dewey Decimal Classification

Display constants for cross references

Content designator history:

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

Subfield $z - Table identification [redefined, 2008]: Subfield $z was redefined as repeatable.