These stealth zones are places where players avoid enemy sight-lines, to hide their presence, and to ensure silent movement. Most missions involving these have rules to restrain from discharging a firearm. If this is ignored, the mission fails no matter what. Some of these are even paired with the snake-wire cam zone to monitor enemy presence. Pairing with the welding torch area, this could mean the player must act quick and get inside after the door is destroyed with a torch, or just hide when enemies come and investigate.