We're reasonably formal - uniforms and belts (but t-shirts in the summer - the AC isn't too good, and some schools don't have it at all), and also formal address - Sir/Ma'am, Mr./Ms., no swearing, etc. Teaching a martial art, to me, includes teaching responsible use - and if you don't have the discipline to control what you wear and say, it's going to be really hard to teach you discipline in what you do with what you've learned - that's why my Sahbum does it that way, and I agree with him. But I also understand that different situations work for different people - if you do something else and it works for you - cool!