It basically uses an IMAGE not a decal or Shirt or Pant template, to use as a uniform. But it only works in play solo. CODE : 

game.Players.PlayerAdded:connect(function(player)
    player.CharacterAdded:connect(function(character)
		if player:IsInGroup(2653853)then
			if player:GetRankInGroup(2653853) == 5 or player:GetRankInGroup(2653853) == 6 or player:GetRankInGroup(2653853) == 7 or player:GetRankInGroup(2653853) == 13 or player:GetRankInGroup(2653853) == 16 then     
       			local a = character:WaitForChild("Shirt")
        		local b = character:WaitForChild("Pants")
        		wait(.05)
        		a.ShirtTemplate = "http://www.roblox.com/Asset/?id=333567143"
        		b.PantsTemplate = "http://www.roblox.com/Asset/?id=333567213"
end
end
end)
end)
Anonymous