What are the exact criteria for a question to have VLQ as a flag option?

Question

I am very confused. The VLQ flag is automatically deemed helpful when the question is closed. However, it doesn't always appear on a question, and its appearance is very inconsistent (IMO).

Known criteria for questions to have a VLQ option

• Must be less than 48 hours old
• Must be open
• Must not have a positive score (i.e., only 0 or lower can have VLQ)

The rest are very unclear to me, however.

Since we get ~20 "lost soul" questions on MSE every day, I decided to pick them as sources, flagging every "lost soul" question as VLQ. Here are some of my collected data:

Score, CV, Comments, HasVLQ
0,     0,  0,        1
0,     1,  0,        1
-1,    0,  0,        1
-1,    1,  0,        1
-1,    1,  1,        1
-2,    0,  1,        1
-2,    2,  0,        0
-2,    2,  0,        1
-2,    3,  1,        0
-3,    2,  1,        1
-3,    3,  1,        0
-4,    1,  1,        0
-4,    2,  0,        1
-4,    4,  0,        0
-5,    3,  0,        1
-3,    2,  0,        0 (edited)

The first column is the score of the questions when I see it. The second column is the number of pending CVs (you need 3k reputation to see). The third column is the number of comments under the question (I haven't seen OP comments, so this is only "comments by others"). The fourth column is 0 or 1, indicating the presence of VLQ options. A few words in a pair of parentheses may follow, indicating that there's something special about the question.

Many of the combinations have been seen multiple times.

I am aware of this answer, but if a question already has CV on it, shouldn't it already be in the CV review queue? (I believe nobody would click "Leave Open" for these questions de l'âme en peine.)

I am not able to figure out a consistent rule/criteria from my collected data. Any insights?

Answer 1

In the Q&A "Where is the very low quality flag?" Shog9 answered:

That question is currently being reviewed for closure. As such, it does not require nor will it benefit from Very Low Quality flags - we already know it's potentially problematic, we're now trying to determine how problematic it is and in what way.

See also: Missing "VLQ" flag option in Triage Queue

Where Brad Larson explains:

Changes to VLQ flag availability

So as of a few minutes ago, Very Low Quality won't be an option from within Triage review or from anywhere else while a question is being triaged. We're also taking this opportunity to be a bit proactive with another change that'll be necessary soon: Very Low Quality won't be available for questions that are currently undergoing Close review either.

This moves VLQ one step closer to my intended purpose: catching awful questions that slipped through the cracks somehow. We'll see how that works out in practice...

And, Travis J offers this block diagram:

Some authoritative answers are offered in the question: How should I flag blatantly off-topic questions on Meta.SE: Close or VLQ?.

Also, there is an almost 3 year old question: Explain missing VLQ flag in the UI with no answer.

It's no different than when a question is on hold (as three people whom have commented on this answer did): once enough information has come in the options presented to flaggers are pared down.

Once a question is on-hold pending closure here's all you get:

There's no need to rehash, but new information is acceptable.

User iBug has offered some additional information in a comment, on Mar 7 2019:

"Consider that CVs and flags have a 10-minute delay before kicking the post into the review queue, you're correct. This matches my observation in the past month, when I specifically noted the # of pending CVs and the age of the question".