| COMARC/A | April | 2020 |
| 400 | Variant access point – personal name |
| 410 | Variant access point – corporate body name |
| 415 | Variant access point – territorial or geographical name |
| 420 | Variant access point – family name |
| 430 | Variant access point – title |
| 440 | Variant access point – name/title |
| 443 | Variant access point – conventional name/title for legal and religious texts |
| 450 | Variant access point – topical subject |
| 480 | Variant access point – form, genre or physical characteristics |
This block contains variant access points. From each 4XX field a see reference entry may be generated that should redirect users from the variant access point to the authorized access point in 2XX field.
The indicators and the majority of subfields of the 4XX fields are the same as those in the 2XX fields, therefore the specifications are not repeated in the 4XX fields.
In 4XX fields the following control subfields may be used:
| 2 | System code |
| 3 | Record number |
| 5 | Relationship control |
| 7 | Script of the base access point |
| 8 | Language of cataloguing |
| 9 | Language of the base access point |
The use of control subfields is described in the Control Subfields chapter (before the 2XX block).