On the topic of ID when in NBC kit, I remember being called out one dark and stormy night during a Taceval at Lyneham and having to don full NBC before making my way to ATC, about a mile's walk.
It was hammering down with rain and there were rivers of water everywhere. I happened upon a station guard, also in full NBC, who pointed his SLR at me and asked for my 1250. After much fumbling I found it and was ordered to put it on the ground and step back. When I did this, it floated away on a mini torrent coming down the hill.
The guard put his hand on his hip, sighed heavily, and said, "For God's sake, if you wanted to play Pooh Sticks why didn't you just say so?"