Guidelines for Usage: 450 See From Tracing - Topical Term
NACO LSP Usage:
Do not use this field. Subject authority records are not within the scope of the present NACO LSP program.
LC Usage:
LC usage for the following subfield codes in field 450 is given in LC Guidelines: Tracing and Reference Fields :
$i - Reference instruction phrase
$w - Control subfield
For more information on LC Guidelines, select:
Guidelines for Usage: NACO/LSP and LC