Many do block out names but there’s no real policy to my knowledge. The forum rules can be found below. They include stuff like “don’t be rude” and “don’t insult.” There is a privacy rule too but it’s to personal information - I guess that can be interpreted if it applies to battles.
My rule of thumb is this. If I tag someone I fought, I share. If I don’t, I screen shot to exclude. But I don’t go out of the way to exclude. I almost see it as me giving praise if I felt the opponent put such a worthy team out there that I’d want to post on it. Of course, saying how bad a team is is a different story.
Hope that helps. The end all of it is be respectful.