FYI, Krinkle writes about this in his essay on Patrolling,

MediaWiki has a system for this already (RCPatrol), but some years back different communities decided to turn off this feature (for all but more advanced users). In English, my understanding is that some users objected to how the flag is displayed on RecentChanges (with a !).

"for all but more advanced users" may be combining two issues. My understanding is that there are two distinct concepts:

1. Whether wgRCPatrol is enabled. It is disabled by default on Wikimedia wikis (I didn't realize that), but enabled on 74 wikis.
2. Which users have the right to do 'patrol' actions. If a user has this right, they can do RecentChanges patrol, NewPages patrol (enabled almost everywhere), both, or neither, depending which is enabled on their wiki. Which users get 'patrol' also varies by wiki. (Users on English Wikipedia can also do PageTriage/PageCuration if they have 'patrol', which uses NPPatrol).

but enabled on 74 wikis.

91 wikis actually (72 individual *wiki, wikidata is a dblist of 2, and wikivoyage a dblist of 17).

Some interesting comments from @Mattflaschen-WMF on the notion of including Patrolled status in the ERI feed:

"We should bear in mind that the instant an edit has been made, it will only be patrolled if the user has autopatrol (the right to patrol their own edits).

Knowing an edit was auto-patrolled is somewhat relevant (since only at least somewhat trusted users should have autopatrol). But by definition most edits will not be patrolled here, so it could be somewhat confusing.

If we add actions, we could include the patrol action. "Previously made edit 123 was just patrolled".

Also, NewPage patrol (patrolling the first edit of a new page) is enabled almost everywhere, but not RC."

I don't understand the last two comments, about 1) actions and 2) NewPage patrol. Is the latter a separate patrol flag?

1. Say at 8 PM I make an edit to Earth. I don't have autopatrol, so by definition it goes across the ERI feed as unpatrolled (if we have that field). We'll say it's revision ID 123. Later at 8:05 PM someone patrols revision ID 123. We could hypothetically then send a feed event "Revision ID 123, an edit to Earth, was just patrolled".

2. There are two kinds of patrolling, but they both use the same rights, 'patrol' (patrol other people's edits) and 'autopatrol' (patrol your own edit):

2a. RC Patrol is disabled on most WMF wikis, but it allows patrolling edits in general.
2b. NP Patrol is enabled on almost every WMF wiki. It allows patrolling only new pages (the first edit of a page). It is used at https://en.wikipedia.org/wiki/Special:NewPages (core feature, not PageCuration) and https://en.wikipedia.org/wiki/Special:NewPagesFeed (PageCuration, which is only available on enwiki and test wikis).

What is the priority of this task, and is it expected to be started/completed by the end of this quarter?

@Mattflaschen-WMF helpfully explained:

Say at 8 PM I make an edit to Earth. I don't have autopatrol, so by definition it goes across the ERI feed as unpatrolled (if we have that field). We'll say it's revision ID 123. Later at 8:05 PM someone patrols revision ID 123. We could hypothetically then send a feed event "Revision ID 123, an edit to Earth, was just patrolled".

Got it. Thanks. This is a crucial point, so let's take it one step further (assume we've enabled RC patrol):

Say at 8:06, I make a search on the RC page with a setting that filters out Patrolled edits. Is there a practical way for us to make it so that I'll filter out that 8PM edit to Earth? I.e., does the filter necessarily just read back the record of all the edits and return all the ones that weren't patrolled when they were made? (In which case the whole idea is kind of useless except for autopatrolled.) Or is there any way to work this--assuming we think it's valuable enough--so that the filter can check for an updated status of edits? If we had to reload the page when the Patrolled filter was used, that could be reasonable...

In T142782#2816154, @jmatazzoni wrote:

@Mattflaschen-WMF helpfully explained:

Say at 8 PM I make an edit to Earth. I don't have autopatrol, so by definition it goes across the ERI feed as unpatrolled (if we have that field). We'll say it's revision ID 123. Later at 8:05 PM someone patrols revision ID 123. We could hypothetically then send a feed event "Revision ID 123, an edit to Earth, was just patrolled".

Got it. Thanks. This is a crucial point, so let's take it one step further (assume we've enabled RC patrol):

Say at 8:06, I make a search on the RC page with a setting that filters out Patrolled edits. Is there a practical way for us to make it so that I'll filter out that 8PM edit to Earth?

Yes, this is already implemented (the new UI will be different, and will also need hideunpatrolled, though). https://www.mediawiki.org/wiki/Special:RecentChanges has "Hide patrolled edits", and this is how it works. (You have to be an admin to see it, so you could ask someone, e.g. Roan to show you.)

Great. Thanks.

I'm contacting Polish Wikipedia now. They are not on the list.

Polish Wikipedia uses Flagged revisions. What would be the compatibility with RCPatrol?

In T142782#3046931, @Trizek-WMF wrote:

Polish Wikipedia uses Flagged revisions. What would be the compatibility with RCPatrol?

They are orthogonal systems and should work separately without issue. In fact, FlaggedRevs even has special RCPatrol-integrations available so that it will synchronise its review system into the patrol system if enabled. It automatically marks-as-patrolled any edits that are reviewed through the FlaggedRevs system to avoid duplicate efforts.

There are various wikis that already have RCPatrol and flaggedrevs enabled. Compare https://github.com/wikimedia/operations-mediawiki-config/blob/master/dblists/flaggedrevs.dblist and https://noc.wikimedia.org/conf/InitialiseSettings.php.txt (search for RCPatrol).

In T142782#3047031, @Krinkle wrote:

In T142782#3046931, @Trizek-WMF wrote:

Polish Wikipedia uses Flagged revisions. What would be the compatibility with RCPatrol?

They are orthogonal systems and should work separately without issue. In fact, FlaggedRevs even has special RCPatrol-integrations available so that it will synchronise its review system into the patrol system if enabled. It automatically marks-as-patrolled any edits that are reviewed through the FlaggedRevs system to avoid duplicate efforts.

Thanks! I didn't fould that information in the documentation.
That synchronisation will ease the deployment, because it will be invisible to the users.

There are various wikis that already have RCPatrol and flaggedrevs enabled. Compare https://github.com/wikimedia/operations-mediawiki-config/blob/master/dblists/flaggedrevs.dblist and https://noc.wikimedia.org/conf/InitialiseSettings.php.txt (search for RCPatrol).

I'll look at it to identify which wikis have FlaggedRevs but not RCPatrol too.

Thank you @Quiddity!

If this task is about the analysis, why not making a followup one for everything else? otherwise it looks like Nick still has work to do here, which I don't think is the case.