The Red Squad (or Cadet Training Squadron 47) was an elite group of Starfleet Academy cadets that received advanced classes of field training.
In 2372, the Red Squad was used by James Leyton to sabotage Earth's main power grid in his attempted coup. (DS9: "Homefront", "Paradise Lost")
Alexandra Dalton turned down Red Squad membership, citing its over-eagerness for battle. (Star Trek: Banshee Squadron)