In the spirit of the recent thread Returning a Dish Because You Don't Like It- Should You Have to Pay For It? if you take a bottle of wine to a BYO restaurant and the waiter removes the cork and pours the wine only for you to discover that the wine has turned to vinegar, is the restaurant within its rights to charge you corkage? Would it make a difference if you bought a bottle of wine from the winelist? Is the corkage for opening the bottle and use of glassware or to compensate the restaurant for the lost profit margin because you aren't ordering any beverages?