Developers can opt out of this universal system if they like, but otherwise any time a user reports a comment in a game’s community area, it’ll be “added to a queue for our moderation team to review”.
If that comment is found to have violated Steam’s (quite strict) community guidelines, it’ll be removed by the moderation team, while repeat or extreme offenders will have action taken against them.
Valve has long monitored things such as user reviews and screenshots, but this will be the first time it’s intervened in community discussion, something the company has traditionally “been hesitant to get involved in”, because Valve “didn’t want to step on the toes of game developers that want to have their own style of communication with players and their own set of guidelines for behaviour”.
The company explains in this blog that the reason for this move is actually down to developers, who “would actually prefer for us to take a more active role in discussion boards, at least to the extent of handling posts that are reported by other players”.
You can read the full community guidelines here, while there’s a detailed rundown of Valve’s “best practices” for moderation and banning here.