The honour-all-cards rule requires a merchant to accept all cards. I have two points on that.
Paul Jewer from Sobeys, in his testimony, said that some sort of compromise on the honour-all-cards rule wouldn't work for merchants either. If they advertise that they accept a certain type of card, like Interac, American Express, Visa, or MasterCard, to surprise the customer with the fact that they won't accept that type isn't workable in an operating environment.
For the consumer it creates an untenable situation. We rigorously enforce the honour-all-cards rule. Some Canadians were being differentially treated in the United States at gas stations because of some technical glitches we had to work through. We've had situations where Canadians working abroad have been told that Canadian cards weren't accepted. Underlying any sort of payment system where there isn't inherent value in the vehicle--cash, Interac, American Express, Visa--the card itself has no inherent value.