As there are 2 threads, I will post this here too:
You can not put FALL in your Motto, just as you can not put EG in your motto.
FALL I kind of understand in a warped way too cautious kind of way. Not because of being a replacement for FAIL as what would be wrong with that really? But, because of it being F ALL possibly, but even that is a bit of a stretch really.
I preferred when bios/mottos were only banned if reported or caught as being offensive as I am sure 99.999% of the use of FALL and EG in mottos would be of the inoffensive variety.
It is possible to put both FALL and EG in your bio, but not in your motto.