| 28N18531 | U1725 | MINISTRY OF DEFENCE AIR DOMESTIC R FERENCE NUMBER USE ONLY |
| J | K7766 | BRITISH STANDARDS INSTITUTION |
| SP121J | K1207 | BROWN BROTHERS ENGINEERING |
| SP121J | K7766 | BRITISH STANDARDS INSTITUTION |
| SP121 | K7766 | BRITISH STANDARDS INSTITUTION |
| SP121-J | K7766 | BRITISH STANDARDS INSTITUTION |