What causes Moderator Action log entries to be removed?


Well-known member
I was reviewing the "Moderator Actions" log in a large thread on my forum a few days ago, and it clearly listed about a dozen posts that a moderator had deleted. Checking today, those deleted posts are no longer there, despite the fact that no other recent moderation actions have been added to that log.

Of course, I see the note that "Previous moderation action logs may have been removed," but there is no explanation as to why that may be. What triggers this pruning process?