In California you can actually wear a button-down /T-shirt/ anywhere you please, but that would make you a "hipster," which is looked down upon in some circles. YMMV.
On When You May Wear a Button-Down Shirt
In California you can actually wear a button-down /T-shirt/ anywhere you please, but that would make you a "hipster," which is looked down upon in some circles. YMMV.