| 401 USER NUMBER | The unique user number |
| 402 PA TO USER SEQUENCE NUMBER | Used to verify reception of files |
| 403 JD OF RESPONSE | JD and fraction when file was generated |
| 404 REQUEST REJECTION | Acceptance or rejection of each group |
| 405-409 | NOT ASSIGNED |
| 410 REDUCED DATA | Return data in reduced form |
| 411-419 | NOT ASSIGNED |
| 420-429 | NEVER DEFINED - For custom output format |
| 430 EXTINCTION DATA | Information on nightly extinction |
| 431-433 | NOT ASSIGNED |
| 434 TRANSFORMATION DATA | Information on measured transformation values |
| 435-439 | NOT ASSIGNED |
| 440 FILTER DETECTOR STATISTICS | Nightly statistics on each filter-detector |
| 441 TELESCOPE STATISTICS | Nightly statistics on each telescope |
| 442 HOURLY STATISTICS | Hourly statistics on general performance |
| 443-449 | NOT ASSIGNED |
| 450 ACCOUNTING INFORMATION | Observing time statistics and totals |