Current status

1. Curation toolbar code is loaded in the user's browser (not yet visible in the user interface) if the following are all true:
   1. User is logged in
   2. User has patrol right
   3. User is viewing an article *not* in the Draft namespace
   4. User did not come from Special:NewPages
   5. Article needs triage
   6. User is not viewing their own article (unless they have autopatrol right)

2. Once the code is loaded, we then evaluate two things to determine if we should show the toolbar to the user.
   1. 1. The ?showcurationtoolbar=1 query parameter is present, indicating that the user came from clicking "Review" on "Special:NewPagesFeed", or that they clicked "Next" from a page where they had the toolbar open. If this parameter is present we show the toolbar in maximized format.
         1. The above was the result of two business rules changes in October: one was to assume that users clicking from NewPagesFeed would want to always have the toolbar code loaded (hence the query parameter). The other was that we could show the toolbar maximized by default in this situation rather than read the user's preferences.
   2. If the showcurationtoolbar=1 parameter is not present, then check if the user accessed Special:NewPagesFeed in the last 24 hours.
      1. If we don't see any indication that the user visited Special:NewPagesFeed in the last 24 hours, do not show the toolbar. The user can click on "Curate this article" on the left in "Tools" to see the toolbar.
         1. If we see that they accessed within the last 24 hours, then read their preferences for whether to show the toolbar maximized, minimized, or hidden (in which case "Curate this article" link text in the Tools menu). The preferences are always set based on what the user's last interaction with the toolbar was.

Possible changes

1. None. Let users override this with Gadget CSS if they really don't want to see the toolbar ever, or let them manually remove showcurationtoolbar=1 from the URL.

2. Don't assume maximized display when showcurationtoolbar=1 is in the URL. Instead, read from their preferences about how they last had the toolbar displayed (hidden, minimized, maximized)

3. Remove showcurationtoolbar query parameter and keep the 24 hour last use check. Not recommended. The way we check to see if the user visited Special:NewPagesFeed requires getting a value from the server. Because of how MediaWiki's caching layer works, we may not always have 100% certainty that this value is present on the page, unless the user does a hard refresh (Ctrl+Shift+R). If we remove it, we might end up with users saying that the minimized or maximized toolbar doesn't show up for them as they expected.

4. Implement a gadget preference and forget the whole concept of tracking last 24 hour use., as suggested in T207482

5. Forget about the 24 hour last use concept, remove the showcurationtoolbar=1 param, and always show what the last display state was. In this version we'd always read the user preferences to see how they last interacted with the toolbar, and display it the same way (minimized, maximized, hidden). We could remove the code on the server side that tracks last use of PageTriage too.