MARC 21 Format for Authority Data

National Level Requirements

Tracing and Reference Fields

1999 Edition
Update No. 1 (October 2001) through Update No. 12 (October 2010)

The subfields below pertain to special subfields used with the 4XX and 5XX fields. For a complete listing of the subfields used for either the 4XX and 5XX fields, see their individual pages.


TRACING FIELDS
   $i  Relationship information        (current)            A
   $i  Reference instruction phrase    (earlier)            A
   $w  Control subfield                                     A 
   $4  Relationship code                                    O