| COMARC/B | February | 2021 |
Field 964 contains a variant form of the subject heading for a name/title entered in field 604.
| INDICATOR | VALUE | MEANING |
| 1 | Not defined | |
| 2 | Form of name indicator | |
| ⊔ | Not a conventional name/title for legal and religious texts | |
| 1 | Conventional name/title for legal and religious texts entered under country or other geographical name | |
| 2 | Conventional name/title for legal and religious texts entered under other form |
The second indicator is entered only for subject headings for a conventional name/title for legal and religious texts. Value "1" is used for geographical names under jurisdiction, whereas value "2" is used for names of churches.
This field is used for entering variant forms of those subject headings that are not linked to authority records. Enter the forms that differ from the form in field 604. The search is simultaneously performed through fields 604 and 964.
The subfield 6 – Linking data must always be filled in, since it is used to link all forms of a subject heading (see examples 1, 2). Field 604 is linked to a corresponding field 964 by entering the same number (01–99) in subfield 6 of both fields. If more than one field 964 corresponds to a field 604, enter the same number in subfield 6 of all corresponding 964 fields.