We need to investigate the technical details of the current watchlist and get a good understanding of it before making a plan for global watchlists.
- Add to the documentation at https://www.mediawiki.org/wiki/Manual:Watchlist so that all the relevant details of how watchlists actually work are covered there. In particular: What actually happens when you view your watchlist? What happens when you view a page on your watchlist?
Note: the TCB team has done a lot of watchlist refactoring recently, as preparation for their work on T100508: Watchlist expiry: Watch pages for a specified time frame (2013). I think Adam Shorland (Addshore) was the lead on the refactoring; talk to him for the inside knowledge.