IMO, a tax receipt should be issued for the FMV of the goods donated, no different from when I donate a computer to a charity and they give me a receipt based on what they deem the FMV to be. In this case, the FMV is a easily derived from the receipt, whereas in my example, valuing used goods can in fact be quite a nightmare. Through a charity my wife serves on the Board of we 'buy Christmas' for a family every year, and the charity gives a receipt for the value of everything you provide as long as you keep the receipt from your purchase. Whether was paid for in cash, gift card or store credit doesn't matter.

I think I may give the CRA a no-names call tomorrow and see what they say about about receipts for food and similar consumable goods.