| COMARC/A | October | 2020 |
| 100 | General processing data |
| 101 | Language of the entity |
| 102 | Nationality of the entity |
| 106 | Access point used as subject |
| 120 | Coded data for personal name |
| 123 | Coded data for geographical name |
| 128 | Coded data for form of musical work and key |
| 150 | Coded data for corporate name |
| 152 | Rules |
| 154 | Coded data for title |
| 160 | Geographic area code |
| 180 | Coded data for form, genre or physical characteristics |
| 190 | Date of birth/beginning* |
| 191 | Date of death/ending* |
| 192 | Subtype of entity* |
This block contains coded fields. Field 100 is mandatory in every record. Other fields are entered regarding the type of entity in field 2XX.