If I get any type of notification email, and click on the link to go to the relevant page, that should mark the onwiki Notification as "read" and decrease the red-badge number.
Eg. Alice reverts my edit at article [Foo]. I receive an email. I click the link and see the diff. The Notification for that revert is automagically marked as "read".
Eg.2. Bob Mentions me in a talkpage discussion. I receive an email. I click the link and visit the thread. The Notification for that Mention is automagically marked as "read".
This is how it currently works for usertalkpage messages (yay!). We'd love for that functionality to be expanded.
Version: unspecified
Severity: enhancement