Aye, I know what you mean, Keith but I don\'t think they\'d DEMAND it (or am I being a bit naive).
If the shop has said that they\'ll give the discount to NESA members, then I don\'t really see the problem.
I don\'t know if it srill applies, but I remember when there were certain high street stores offering discounts to members of various Trades Unions........doesn\'t matter if you\'d ever shopped there before, but if you had your union card with you, you\'d get the discount.