| BS 1 | Repeated identifier or attempt to reorder suffices within pointer. |
| BS 2 | Sub-file not present. |
| BS 3 | Illegal renaming, first parameter has a value set missing. |
| BS 4 | File or sub-file identifier omitted. |
| BS 5 | Attempt to give a pointer a new suffix. |
| BS 6 | Sub-file wrong type. |
| BS 7 | File created by an earlier version of Genstat. |
| BS 8 | Sub-file or structure not present. |
| BS 9 | Attempt to write to a protected file (incorrect password). |
| BS 10 | I/O error or mark 4 file. |
| BS 11 | Clash of structure types. |
| BS 12 | Attempt to give a procedure an illegal name. |
| BS 13 | Attempt to give a procedure an directive name. |
| BS 14 | Subfile name already in target file (could be system reserved name). |
| BS 15 | Output channel is also an input channel. |
| BS 16 | Attempt to add 2 subfiles with the same name to target file. |
| BS 17 | Userfile not found. |
| BS 18 | Incompatible backing store attached (created by another version of Genstat). |
| BS 19 | Length of units vector has been changed. |
| BS 20 | Target file opened read only – a write request given. |
| BS 21 | File incomplete or corrupted. |