Correct, and just a note, they do count infants into the party size. While traveling with our 6 month old GD, whenever we made ADRs, they always included her, even though she was not eating.
If you are on the dining plan, gratuity is included anyway...I would assume that a 6 month old would not count, since the baby is obviously not being attended to by your server.
You would think so...but that is not the case with WDW. I had more than 12 ADRs and yes, they counted the baby towards the party size for EVERY ADR we had. Not that it mattered to me, but did find this strange--I questioned it everytime I called and added another ADR.