It may be necessary to add, change, or delete 663 or 664 fields and/or add or change control subfields ($w) to cross-references on existing authority records.

1.  Conversion from complex reference to regular reference

Change the record on which the complex reference is traced by changing the $w control subfield and correcting the tag, if necessary.

For a see reference, search the database for the record with the 664 field.  If found, cancel it following the normal procedures for record cancellation.  If not found, assume that the complex reference has already been cancelled.  For see also references recorded in 663 fields, also delete the 663 field from the record for the heading referred from.

2.  Conversion from regular reference to complex See or See Also reference

Change the $w control subfield for the reference by adding a value b or c in the 4th position.  Correct the tag if necessary.  For see also references, also change the record for the heading referred from, and add the 663 field to it.

3.  Change to an Existing Complex Reference

If the reference is, and will remain, a "see" (664) reference, and if the change is to the refer-to or refer-from lines, change the name authority record(s) on which the complex reference is traced.

If the reference is, and will remain a "see also" (663) reference, adjust the text of the reference as necessary.  If the change is to the refer-to or refer-from lines, also change the name authority records on which the reference is traced.

See also:

Section II:  Additions and Changes to Authority Records