| 5K6169 | U1725 | MINISTRY OF DEFENCE AIR DOMESTIC R FERENCE NUMBER USE ONLY |
| C20 | K7766 | BRITISH STANDARDS INSTITUTION |
| SP93C20 | K0056 | STANDARD RUBBER GROMMETS LTD |
| DEFSTAN53-13 | K0851 | MINISTRY OF DEFENCE DIRECTORATE OF STANDARDIZATION STAN 1 |
| SP93 | K7766 | BRITISH STANDARDS INSTITUTION |
| SP93-C20 | K7766 | BRITISH STANDARDS INSTITUTION |
| SP93C20 | K7766 | BRITISH STANDARDS INSTITUTION |