I see that NoMercy has posted while I'm typing but, in the words of Magnus Magnusson, "I've started so I'll finish" ;-)
NAAFI = Navy, Army and Air Force Institutes.
It runs lots of things (from shops to social clubs) but the term 'the Naafi', as used by NoMercy, refers to the bar used by sqaddies. (Officers drink in their 'mess').
He seems to change his avatar nearly every time he appears here. I seem to recall a picture of a guy, looking like a US game show host, in bright pink clothing being another one of Bob's avatars!