Mark it, call it in
Airman 1st Class Bernard Byer (left) radios in his chemical reconnaisance team's report as Senior Airman Melvin Lucas changes a zone transition point sign during the first peninsula-wide combat employment readiness exercise, or PENCERE of the year. 'ZTP' signs inform other Airmen what sectors they are enter and whether that sector is contaminated with biological or chemical agents. Both Airmen are assigned to the 8th Communications Squadron. (U.S. Air Force photo/SrA Stephen Collier)