Standard operation codes contain x"FA" in the most significant byte. The least significant byte indicates the specific operation.
| CLOSE | Terminates the processing of a file. |
| COMMIT | Releases all record locks in all files held by a run unit. |
| DELETE | Logically removes a record from a file. |
| DELETE FILE | Physically removes the specified file from the physical devices on which it resides. |
| OPEN | Initiates the processing of files. It also performs checking and/or writing of labels and other I/O operations. |
| READ | For sequential access, makes available the next or previous logical record from a file. For random access, makes available a specified record from a disk file. |
| ROLLBACK | Releases all record locks in all files held by a run unit. |
| START | Provides a basis for logical positioning in a relative or indexed file, for subsequent retrieval of records. |
| STEP | Steps to the next physical record. |
| UNLOCK | Releases all record locks held by a run unit on a named file. |
| WRITE | Writes a new record to a file. |
| REWRITE | Replaces an existing record. |
Not all operation codes are appropriate with all file organizations. Each operation code description includes a list of the file organizations for which it is valid, using the following key: