Radar shroud is the name of the special issue equipment used by operator Reaper ( a.k.a. E.W.R.-115 ). It is unlocked by default and can be replaced any time by a diffrent special issue piece of equipment, such as a Fragmentation Grenade or a Tomahawk ( provided that the player has had previously unlocked said Tac. Equipment ).
The Radar Shroud is, technically, a portable jammer, launched by a specialised firearm, possibly a modified M79 GL . The Shroud blocks a specific area around the point of impact, making it look like grayed-out static in the enemy's mini-map, for a limited amount of time. This allows the friendly players to not show up, when firing an unsuppressed firearm, in the mini-map. It also prevents UAV detection. The Radar Shroud is mostly useful for preventing your enemies from planning ahead, giving you an advantage and a chance to ambush them. Extremely useful for defending Hardpoints, or Flags in CTF matches.
The R. Shroud is, much like Recon's T. Dart, destructible. Therefore, it should be launched somewhere where the nemy team is not likely to pay a lot of attention, like high up in a wall or behind some hard cover.