Trainee denoted an individual undergoing some form of training.
In the 2280s Starfleet uniform, Trainees were a separate division, denoted with a red turtleneck. (Star Trek II: The Wrath of Khan; Star Trek III: The Search for Spock; Star Trek VI: The Undiscovered Country)
In the mid 22nd century, Starfleet Trainee Malcolm Reed suffered illness training in the EV simulator at Lunaport. (ENT: "The Catwalk") While trainees, both Malcolm Reed and Charles Tucker III often frequented the 602 Club. (ENT: "Shuttlepod One")
- Presumably, all Starfleet cadets are included. Only those confirmed (by statement or visually) are included.