For most of the spring, I had refundable M fares SFO<-->YYZ that were somewhere between B and H in their flexibility and cost.

This Wednesday night I was trying to book SFO<-->ORD tix (see recent thread about wacky G fare); when I searched for the cheapest refundable itinerary, the search engine returned H on the outbound (O.K.) and V on the return (huh?). I called AA and the agent told me what I figured--that it was too good to be true. But who knows what another agent might have told me. I guess "get it in writing" is indeed the best policy.