Since dmor mentioned the telecom industry, let me just say that when I attended the GSMA Mobile World Congress in Barcelona, everybody (except booth babes) was wearing suits or other "business attire" - technies, sales, marketing, whatever. (I was very clearly an engineer and was there to answer technical questions, and I wore a suit).

[OT: after having been to the trade show, I still don't know what CBOSS do, besides hire lots of models to man their stand...]