It sounds very odd, and quite over officious to me (perhaps they just spoke to the wrong person...)
Since it's now blatantly obvious where it was

, it is true that generally only members of the society would be allowed on the plastic site (and therefore to get to the beer tent), but I'd personally have thought that if you had a trader's pass, or paperwork or whatever, to prove you were trading, and not just some stray mop who had just wandered by, then there'd have been no problem.
Or I should say there
should have been no problem.
You have my full sympathy - it's horrible trading at an event where you don't know anybody and end up all on your own.
In future tell Mark to look out for me if I am there same unit as Steve they will be more than welcome around our unit fire (if we have one).
Ditto - even if it's a "zen" camp fire!!
Debbie
"What a lovely hat! But may I make one teensy suggestion? If it blows off, don't chase it."
Miss Piggy
RIP Edward the avatar cat.