情報來源：https://twitter.com/wojespn?s=20
NBA coaches are no longer required to wear a sports coats during games, sources tell @ZachLowe_NBA and me. Coaches must wear business attire (no track pants during games). Coaches must wear facemasks during games, sources said.
Coaches must wear masks at all times with limited exceptions when at team facilities or arena, during team travel and during practices and games, sources tell ESPN.
教練在比賽期間必須穿正裝，不能穿運動服。
除了例外狀況(沒舉例)外，教練在場館、遷移、練習、比賽的期間都要戴口罩。
《更新》
https://reurl.cc/q8ejW0
The NBA and NBCA also agreed to continue the practice of more casual game
attire, no longer requiring coaches to wear sports jackets, sources said.
Coaches voted more than 2-to-1, sources said, to allow for wearing polo
shirts in games, sources said. Coaches must wear business attire, such as
dress shirts, pants, socks and shoes, sources said. Polo shirts count as a
dress shirt. The NBA will disallow sweat-pants and jogging pants.
找到一篇比較完整的：
1. 西裝外套：可不穿
2. Polo衫：ok
3. 運動服：不ok
心得：
以前好像有一篇教練穿休閒裝vs正裝的討論？