WTF? ?
I've just been invited to a party with the above dress code, and I haven't the faintest idea what it means. To complicate matters further, it's been organised by Hungarians (I'll be one of the few non-Hungarians there), so God alone knows what "business retro" suggests over there given that they normally delight in doing things as differently from everyone else as possible.
Unfortunately, I can't hide in the background because I'll be up on stage interviewing someone, so does anyone have any suggestions?