Where back in the day it may of meant Welshmen originating from around the Cardiff area or River Taff area, now usually mean someone from the whole South Wales area.
A commen misconception though is that all people from Wales are called TAFF..wrong people from North Wales are commenly known as Gogs because North in Welsh is Goggledd.
Saying all that there is also the rumour that TAFF stands for....Thick As Fucking Fuck
by Mike767 February 02, 2008