Appendix A: Control Subfields
Appendix A contains descriptions of four subfields that are used to link field data to specific institutions, to other records, or to other fields. These subfields are defined for several ($0 and $5) or most ($6 and $8) fields in the format, thus their descriptions are brought together in this appendix. The subfields are included in field level subfield lists wherever they are defined, with links to this appendix.
Specific subfield information:
$5 Institution to which field applies (R)
$6 Linkage (NR)
$8 Field link and sequence number (R)
See also:
