I’ve seen the functionality to “sink” and/or “bury” posts on other discussion software, where they seem to be valuable tools for combating trolling, flamewars, and gravedigging. These options can provide for a non-confrontational, discreet alternative to other moderation tools, particularly when forum regulars get dragged along for the mud slinging.
“Sinking” a topic refers to not allowing it’s last updated time to update anymore, such that it can naturally sink down in the list order. This works particularly well as a response to gravedigging, since gentle, public correction can be applied, and then sinking the topic makes sure it will never float back to the top. This is also a strong option against a flame war, as it effectively hastens the natural end without even needing to inform the participants.
“Burying” is essentially the opposite of pinning - rather than showing up at the top of the list of topics, a buried topic is always shown last, after all the topics which are not buried, so that a user has to scroll to the end of the list to find them. This allows those who are tracking the topic to continue, but makes it very unlikely that anyone else will join, effectively doing a soft close on the topic
By “inhibiting” rather than “prohibiting” an unhealthy discussion, there’s far less pushback from those involved in a flamewar than there might be by closing the topic or banning/suspending members, particularly longtime members, and in particular, the participants are less likely to redirect their anger at moderators and admins.