The term pretzel came from snowboarding because of the awkward arm movements required to 270 on and 270 out the other way. Now whether you like it or not our trick names are derived from snowboarding and in snowboarding it has always meant with a min roto of 180, most commonly 270 because otherwise they didn't have to contort there body enough to justify the name. now that it has been adapted to skiing the rules are the same but the reason behind the name is lost.
so saying that a 90 on to frontside 2 out is a pretzel because you changed directions just demeans the trick and makes you look like a retard in front of people that actually know what there doing.
the only time i would MAYBE consider calling a 180+ out a pretzel without a 180+ on is if it is a BS swap to BS 270 out. Although I would defs consider it a pretzel if there was 360+ of sameway swap followed by otherway 270 out
So i guess my rule for pretzels is at least 180+ one way on/during the rail and a 180+ the other way on the dismount.
only one im unsure about is 270 on to brittany.