What are you supposed to wear to the pre-interview dinner? The same suit you will wear the next day? or something different or something more casual???
You def. do not need to wear a suit - you will look absolutely silly! "Business casual" - non jeans and a nice top. Guys can wear a tie, but a jacket is not needed.
I would think it also depends on the venue. I recently went to an interview dinner which was in a non-fancy Chinese restaurant. Even the residents wore jeans, but then again they were not in derm 🙂
I would say for guys some nice pants (not jeans) and nice shirt. The dinners I attended some of the residents wore jeans and nice shoes, shirts or tops (for the female) but then again they were already in. I'll definately be wearing jeans if I attend any pre-interview dinners.