wrote
Radarman RdM Stand radar watch and operate radar equipment.
Radio Electrician RE
Radio Technician RT Maintain radio equipment.
Radioman RM Transmit and receive radio messages. Encipher and decipher
messages.
For current ratings see URL;
http://www.history.navy.mil/faqs/faq...tm#anchor17021
RD - Radarman
RdM - Radarman
RM - Radioman
RMN - Radioman (Radioman)
RMT - Radioman (Telegrapher)
RT - Radio Technician
RT(SR) - Radio Technician (Ship Repair)
"gudmundur" wrote in message

I was an RT, Radio technician initially but the rating was shortly changed
to ET, Electronic Technician during my hitch in WW11, 1944 - 1946. Operators
were RM, Radioman and Radar guys were RDM, Radar Man.