In my world, you can take your suit jacket off in a meeting and roll up your sleeves, and it means, “I’m serious and ready to get to work.”
If you take off your tie, however, it means, “I’m finished and I’m going home.”
It’s not code or symbolism, it’s just how people dress in the business world on the East Coast. And even among suits, there are differences – in the South, men wear cotton and linen suits, as well as seersucker patterns. Wear a seersucker suit in NYC and you’ll be snickered out of the boardroom.
So would a Southerner be wrong to wear a seersucker on Shabbos because it does not meet the accepted codes of formality in NY?
Oh – and in my makom, if you wear a sports-coat, you’re dressing down – acceptable for dinner, not so much for a meeting.