How many times can a post go through each review queue?

Question

I'm aware of what can cause a post to exit a review queue. This question is about what can cause a post to return to a queue that it's already been through.

I know that a post only goes through the First Posts or Late Answers queue once; reviewing those more than once would be kind of silly. And I know that any given suggested edit goes through the Suggested Edits queue only once, though of course subsequent edit proposals can send the same post there again. What about the other three queues?

It sounds like a question can go through the Close queue more than once if the first votes expire and then somebody votes to close again. Is that always the case? Is there a limit, or could a long-running close/reopen war send a question to the queue every time? Do the same rules apply to the Reopen queue and the Close queue?

If a post exits the Low Quality queue, do subsequent NAA or VLQ flags send it back there? I think I was told, as a moderator, that they don't and so I should handle those flags, but I can't find documentation now.

Answer 1

For completeness, I'm just going to include all review queues.

Close Votes

A question can go through this queue an unlimited number of times. However, a new close review item will not be created for the same question until all of the close votes which existed prior to the completion of the previous review task have expired (or are retracted).

Reopen Votes

Functions exactly the same way as Close Votes except has the added complicating factor of an edit that can bump it into the queue.

Help and Improvement (Stack Overflow Only)

Theoretically, it could be unlimited because there is a loop of activity that could cause a question to keep bouncing back and forth between Triage and the Helper queue if reviewers continually disagree. See the Triage item for how this loop breaks. Questions are also only eligible to be in the Helper queue a certain number of days after the Triage task was completed (currently set to 4).

Low Quality Posts

If the post has already had a Low Quality review task, further flags will only appear in the moderator flag queue unless the post has been edited since the last task was completed (or invalidated).

Suggested Edits

Unlimited, because the post isn't the target, but rather the edit to the post.

First Posts

A post will only ever get selected once for this queue.

Late Answers

An answer will only ever get selected once for this queue.

Triage (Stack Overflow Only)

Similar to Help and Improvement, theoretically unlimited due to the loop. However, questions are only eligible to be in the Triage queue for a certain number of days from creation (currently set to 7) so... as many times as is possible within a week.

Note: The selection criteria don't pay attention to whether the task was completed vs invalidated, only that a task existed.