Splinter Cells used a mixture of standardized radio protocol and a language all their own to communicate. In this case, clean meant no complications of any kind. A sleeper was a lethal casualty, enemy combatant; a napper was a nonlethal casualty, enemy combatant. Wildfire meant a Splinter Cell was engaged in an open gun battle, and breakline meant he or she had been compromised, and the mission was in jeopardy. Skyfall meant the operative was now in EE (escape and evasion) mode.