OOPS! Sorry, it would appear that I developed a bad case of CRS disease (or dislexic fingers) as far as the acronym, the correct one is S.E.R.E. (Survive, Evade, Resist, Escape). It's an advanced survival school for (primarily) training air crews how to survive if they're downed behind enemy lines, and what to expect, and how to deal with it (including torture) if you're captured. They also train Special Forces, Rangers, TACP, CCT, PJ's, Force Recon, SEALS, and a lot of other troops that might find themselves in similar situations.
When I went through (as a fresh, snot nosed 19 year old A1C), it was still primarily an Air Force School (at least in my class, we only had one Army guy), but they were running classes through of all Army, Navy, and Marine air crew members, as well as special operations people. I understand that today, each of the services has it's own schools, and it's own training regiment specialized around their missions.
