I had an on-campus interview the other week and got called back for an onsite interview with ~20 other potentials. Monday and Tuesday are business (suit), and there is a dinner/cocktail even Monday which we were told is business casual. There is also a dinner tonight with just the potential employees and a handful of people currently in the program (rather than all the managers and HR people too) I'm trying to get in to. I asked if this was business casual also, and in her next email to the whole group said that casual dress is fine for Sunday's hotel check in and dinner. There will also be two ladies from HR at the hotel to great us. I think casual means nice, non-faded jeans and a polo or sweater. My gf said khakis and a polo, which, I think is still business casual. Any tips?