情报来源：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.
教练在比赛期间必须穿正装，不能穿运动服。
除了例外状况(没举例)外，教练在场馆、迁移、练习、比赛的期间都要戴口罩。
《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.
找到一篇比较完整的：
1. 西装外套：可不穿
2. Polo衫：ok
3. 运动服：不ok
心得：
以前好像有一篇教练穿休闲装vs正装的讨论？