A few years ago (at a UK airline) we stopped using the term "committing" as part of a drive to better train low go-arounds/baulked landings. The new term we used was "dispensing with the alternate" and we used the criteria mentioned by
Denti
The change was made to get across that you weren't actually "committed" until thrust reversers were deployed denoted by PM calling "reverse normal"....
It didn't lessen the arguments about carriage of extra fuel though