Just because jackets are no longer required doesn’t mean you can wear whatever you want on walk around. If you choose to not bring your jacket and it’s 20 degrees somewhere then plan on wearing your short sleeve shirt. I’ve had several FO’S over the years bring sweater (not even black) and light jackets to wear. No go. Don’t put me in that position to have to act like your dad and tell you what you can’t wear. It’s not that hard.