whenasinsilks

I think the main sort of rule is "don't share locked content." After that, commenting on the main post with a comment related to content of said post is 100% desired. Commenting with random unrelated content might get blinked at. Talking to other people but not the OP of the post might get blinked at but lots of people think it's fine (people do it in my comments all the time).

If that's helpful.