| Level | Item |
| Reference Number (click to see whole series/group) | G15/187 |
| Extent | 1 file |
| Title | SECRETARY'S FILES: CENSORSHIP - RADIO TELEPHONE SECURITY |
| Date | 31 Aug 1939 - 20 Sep 1957 |
| Description | Routine correspondence retained on the instructions of the Secretary. |
| Original Reference | M20_01 |