It appears I know nothing about Threat

[Pumpkin]

Browsing the Wiki, I found this.

After 30 minutes of acting as simple threat, these ships will join up with the threatfleet.

This imply there are "simple threat" and "threatfleet" and they are not the same.

I thought there were only one behavior for non-guarding, non-special-forces AI units: roam Human frontier and backstab when possible. I supposed awakened guards, CPA, preemption, Cross Planet Waves, etc were all assigning their ships to that unique threat thing.

Also, I barely remember, now that I'm thinking about it, there is another state where AI ships may patrol a small set of planets. The F3 key gives some interesting info (and often undecipherable to me) when the mouse hover over AI units. Does someone have accurate knowledge on that?

This might be of crucial importance because I'm afraid I wrote completely misleading info (if not plain mistakes) on the wiki (here).
Please help!

[Mánagarmr]

If I remember correctly "Simple threat" behaviour was the only behaviour up until the "Threat fleet" behaviour was implemented, because simple threat was too easy to clean up as they'd just linger on the borders, spread out. The threatfleet instead tries to group up and act as the Special Forces fleet, but with the intent of attacking, not defending.

[Pumpkin]

If I remember correctly "Simple threat" behaviour was the only behaviour up until the "Threat fleet" behaviour was implemented, because simple threat was too easy to clean up as they'd just linger on the borders, spread out. The threatfleet instead tries to group up and act as the Special Forces fleet, but with the intent of attacking, not defending.

Okay. So there are "free but stray" and "threatfleet" modes. Is there only one threatfleet? Can there be multiple? What is the behavioral difference?

There is that elder page about AI Ships Behavior speaking about, for example, melee ships moving while guarding and not allowed to exit their planet, which is obviously outdated.

[Draco18s]

Search the changelog, there might be more details there when it first got implemented.

[tadrinth]

Pretty sure there is only one threat fleet.  The entire point of it is to group up loose AI forces that don't see any weak points. 

[Pumpkin]

Pretty sure there is only one threat fleet.  The entire point of it is to group up loose AI forces that don't see any weak points.

I think so, but the point of the Cross Planet Attack is to menace multiple planets. So CPA would join the "loose" threat?

[Pumpkin]

Search the changelog, there might be more details there when it first got implemented.

Yep, good advise. I did that and, indeed, "normal" threat and the "The" Threat Fleet are two distinct things.

Here are some lines I found.

If a ship is in a part of the galaxy that the AI cannot reasonably easily gather forces from (meaning there's some nasty human chokepoint cutting it off from the AI homeworlds), the AI will no longer try to enlist that ship into the Threatfleet. The "local threat" logic is better in those cases.
(...)
Threat ships behave as they used to for about 30 minutes after being freed, but after that they are switched to an alternate "Threat Fleet" behavior that is somewhat similar to the new Special Forces mechanic.
Note: this only happens on Difficulty 6+, as it's not the AI getting anything extra, it's just behaving more intelligently (in theory) with what it has.
(...)
If an AI homeworld or core world is under attack, the threat fleet will rally to defend it.
Otherwise, if it sees an accessible non-AI planet with a significant human presence that it thinks it can take out, it goes to attack that (it will still pool up at the entry wormhole in some cases, until enough of them are there to pass the threshold, so they don't march in to the grinder one-by-one).
Otherwise, it picks a planet in AI territory to hang out at until either of the two above conditions are met.
When a special forces alarm post is triggered it converts all special forces in the galaxy directly into threat-fleet.

Also, I removed that line from the wiki as I'm really not sure the Threat Fleet may intercept Human attacks:

Threat may intercept Human invasions: while this is more the role of the [[AI War:Special Forces|Special Forces]], the Threat Fleet might join a battle in AI territory if no back-stab opportunity is left by the Human move.

I improved the wiki's Threat page but I'm still not satisfied. I really need some help, here, or at least a proofreading. This topic is a particularly obscure one; I can't imagine players could understand the threat / threatfleet distinction from the game alone.