First of all, whenever US leaves base, they are ALWAYS at risk of being shot at while they are outside of base doing what they do, or making there way to a claimed area, RP or not (Unless GM/Staff Enforced)
Secondly, US always have their weapons out when outside of base for the aforementioned reason, although they may be afraid of traps the quickdraw clause in the rules makes being "gunned downed point-blank" not only unlikely, but also punishable if the scenario you are presenting in the sentence containing the quote were to be if US were talking to Tali face to face and one of them decides to pull out their guns and kill them. Speaking of such scenario being gunned down like that is highly unlikely due to the fact that US always having their weapons out when outside of base. The only case this would really apply to is if a Tali were to ambush them from an area they were looking in, however I doubt the Concealment clause would reasonably cover that.
Speaking of which...
We do this anyway. We know the US would immediately kill us if they see us with our weapons out.
As our ROE is "All US outside of Base/Claimed area are KOS" I'd imagine the US ROE are along the lines of "Any Tali observed to be possessing a weapon are KOS, Otherwise they are not KOS.", This concealment clause wouldn't do anything.
See, this clause is made completely unnecessary due to one simple fact: The US are the pray, Taliban are the hunters.
Not only that, this clause would actually restrict roleplay and the following scenarios would not be possible if this were to be implemented.
1. Drug deals gone bad
Some US soldiers wants to sell [Insert Narcotics] to some Taliban soldiers, however they find out the [Insert Narcotics] and this retaliate by starting a shootout.
2. Checkpoint inspection gone base
A US soldier stops a car at a checkpoint, the driver is asked to pop open the trunk however he makes the excuse that he can't open the trunk from the drivers seat and has to unlock it with his key. He opens the trunk, pulls out a sawed off shotgun and kills the guardsman.
3. Kidnaping
3 US Soldiers are on patrol on a busy street, they are approached by 7 guys who split up to surround them and draw their weapons. Hopelessly out gunned, out numbered, and out positioned, They surrender and are captured.
This is a Military Roleplay Server featuring insurgents. There are going to be gunfights and there is literally no need to restrict those gunfights outside of the quickdraw rule in anyway whatsoever.