Feature summary: Users to get an option for opting in to notifications when some other user edits (or creates) a page in their userspace such as their subpages.

See also T3876, following which users are given an option to opt in to notifications when some other user edits (or creates) their user page. The possibility of creating such a feature for other user subpages was also discussed there.

Benefits: As with user pages, any content in user subpages is also perceived as written by or closely associated with the user in whose userspace it is. Often, user subpages are linked to from the user's root page, and sometimes even transcluded. Thus clearly, similar to root user pages, userspace pages also play a part in shaping up user's community standing. Similar to T3876, minor edits made by bots would ideally not trigger a notification.

I'm aware that some people use user subpages to host todo-lists, tasks, drafts, etc. but they could easily simply not enable this, which I think works fine on home wikis or wikis where the user is sufficiently active. However, there is no good way to patrol one's user subpages on wikis where one is not regularly active or smaller wikis where there aren't many users to do patrolling regularly to address this, and this is especially needed for cross-wiki patrollers who are often targets of vandalism or attacks which may be on a wiki they don't usually visit and may lead to it being unnoticed for long time, which sounds very uncomfortable.