As for the paper of unknown nature, I think he means 'content' or 'purpose'. What no one has mentioned is:
Laundered paper of unknown origin
On Vulcan QRA I also had a spare pair of socks. On call out I would don one pair. In the aircraft I could don the second pair if it was cold. In the right leg pocket would be a melted, resolidified, melted etc Mars bar. Sometimes this would be laundered too unless the dogs got to it first.
One time our copilot's right leg pocket contained a half-eaten chicken leg. Later, about a month later, it contained about a quarter of a half-eaten chicken leg and a large quantity of well fed and very happy maggots.
