That's a good point, Woody - they'd think you were nuts if you wore a suit during a CELTA course, but clobber that could cramp impressive high-kicking Hong Kong wirework-style actual teaching post-CELTA isn't to be frowned upon. The implication might therefore be that people who wear suits aren't/shouldn't still be slogging away in classrooms.A suit might also restrict your energetic antics, which are certainly encouraged on CELTA type courses.
Ah, but then, we were "forgetting" about 'smart casual' - y'know, semi-ironed (semi-crumpled?) shirt and slack slacks. (Didn't somebody mention this earlier? Probably lolwhites - again! Or it might've been Iain).
But I do agree that super-strict very very smart dress codes smack more of business than education (and the strange thing is that 'Business English' generally pays peanuts...but we all know the one that ends with monkeys (then shrieks and tears)).
Next idea for discussion: a tie (neck tie) can restrict hostages' movements - handy when your CELTA trainers haven't awarded you an A grade, or even a B.