YS apparently does have a dress code, and when we dined there last week, we made sure to dress appropriately. However, I noticed that in our seating area, we were literally the only table that had done so- everyone else was in tshirts, flip flops, etc. We weren't 'dressed to the nines' or anything, but I had on a nice skirt and top, and DBF wore khaki pants and a collared shirt. He was complaining about having to be dressy when everyone around us was much, much less so. It was actually a little disappointing- this was our one 'nice' dinner, and it slightly took away from the ambience.
Sarah