The first delicatessen generated in the game will always stock food aligned with whatever food-related conducts you have kept up until that point, except for foodless, in which case it stocks only decadent food to tempt you into breaking it.

Shopkeepers in delicatessens who are sold corpses should magically turn the corpses into tins of that monster with a random beatitude. As well, delicatessen shopkeepers rarely generate carrying a tinning kit.

Delicatessens buy and sell tin openers, though they may not actually generate with any (it would internally appear on the list of the shop’s wares, but with 0 frequency).

Also, the canned food factory shop type in UnNetHack should buy and sell these.

If you are a Monk and the game decides to generate a delicatessen, replace it with a health food store 80% of the time. This is independent from the special case for health food stores in Minetown.

Delicatessen shopkeepers chide you if you eat something while in their shop that doesn’t belong to them and that you didn’t buy from them. “Buy something or get out!”