[pfapfap]

I go with intent, and more the "older" way of NL. If the person obviously intended to raise, I let it stand. If it's an afterthought, too bad so sad no raise. In cash games, anyway. In tournaments, players can be nittier.

Note that in some cardrooms, calling a string bet is done by players, so don't expect the dealer to speak up. But regardless of what you do at home, DO NOT string bet at a cardroom. Announce all action before moving chips.