[airforcebluecollector]

Ray,

I believe the Engineers "E" Brevet was authorised by AMO 1019 in September 1942 along with the Navigators "N" Brevet and the Bomb Aimers "B" Brevet.
A Radio Observers "RO" Brevet was introduced in 1941 or 1942 also and Wireless Operators who were aircrew wore an "S" Brevet introduced by AMO1242 in 1943.
An Air Gunners "AG" brevet was introduced by AMO 547 in December 1939 replacing the Air Gunners winged bullet.
A Meteorological Observers "M" brevet was also introduced near the end of the war.
I've seen reference at various times to other commonwealth nations brevets, for example Canadian types, being worn by RAF personnel who trained overseas as part of the BCATP (e.g. Wireless Air Gunner "WAG", I don't think this was ever formally adopted by the RAF but will stand corrected if anyone can confirm otherwise).