The Cloaking superflag makes the player completely invisible out the window when being carried by a tank. The tank is still fully visible on the radar, and it is possible to detect tank movement out the window by observing tank tracks and jump landings.
Tanks with the Cloaking superflag can not be killed by a player carrying the Laser superflag. Because of this, the Cloaking superflag has become very useful on maps where it's easy for a player to be continuously spawn killed with a Laser superflag by adding many Cloaking superflags in the spawn area. For example, this is used on the team bases in Missile War 2.3.