Alerting of negative inferences
Suppose a partnership is playing a convention which is fairly likely to come up (e.g. "1 over 1 is artificial and shows 2 or fewer hearts", which is often seen in 2-over-1 systems). Obviously, 1 is alertable. If the opener bids 1 and the responder bids something other than 1, and the opponents ask what it means, the opener would of course have to say something like "it's a natural bid, but my partner would normally bid 1 with 2 or fewer hearts, so they likely have heart support"; the negative inference is part of the partnership agreement so it should be explained when the opponents ask.
My question is: in this sort of situation, should natural bids other than 1 be alerted, so that the opponents know that there's something to ask about? (What about bids like a natural 2NT, which most players would interpret as denying hearts even in the absence of the negative inference?)