Add a filter to the RC Filters set that enables (logged in) users to identify changes to pages on their Watchlist. There will be three options, as shown below (with proposed language) below:
===Watchlisted pages
**On Watchlist**
Changes to pages on your Watchlist.
**New Watchlist changes**
Changes to Watchlisted pages you haven't visited since the changes occurred.
**Not on Watchlist**
Everything except changes to your Watchlisted pages.
=Functionality
- If the user is not logged in, show the filter group as grayed out. When the user hovers over it, a tooltip explains: "These filters are available for logged-in users only."
- "New Watchlist changes" is a subset of "On Watchlist." If the user selects both filters, "New" is shown in the "no-effect" display state.
- The "Not on Watchlist" option finds EVERYTHING that is not an "On Watchlist" change. I.e., together, "On Watchlist" and "Not on Watchlist" provide total coverage.
- Position of group: add to the end of the existing menu.