As we mentioned above in section 5, the obligation to say Birkat Ha-mazon applies only when eating a substantive amount. It is preferable to say it as soon as the meal is over. Even if this was not done, the blessing may still be said, as long as the person who ate is still full.
Some go above and beyond, washing their fingers before the recitation of Birkat Ha-mazon. This is called mayim aĥaronim (afterwater).
Birkat Ha-mazon should be said in the room where the meal was eaten. One should not slouch or sprawl, but rather sit in a dignified fashion.
If three or more men ate together, prior to Birkat Ha-mazon they make a zimun, a responsive passage in which one of them invites the others to praise God together. If there are ten men, they add the name of God to this passage. If three or more women ate together (with fewer than three men), they are permitted to make a zimun, but are not required to do so.