**Background:**
Research at T289534#7309057 suggests most links to disambiguation pages occur with wikitext editing. The user probably isn't aware that they are adding such links, as there is no feedback on what the link is, even in preview. They would need to browse to the page itself before discovering that it's not the page they intended to link to.
**Proposed solution:**
When a user types a link to a disambiguation page, we show a warning in the form of a toast notification indicating that it is probably not the page they intended to link to.
There is a proof of concept user script that can be tried out at T288589. It offers suggestions for what the user //may// have wanted to link to, but we won't be doing this because a simple prefix search doesn't always deliver the right pages (see comment at T145622#2689937).
{F34600933}
**Acceptance Criteria:**
* Show a notification after a user types a link to a disambiguation page, similar to the mockup.
* All links should open in a new tab.
* The "disambiguation page" link should link to centralized documentation on mediawiki.org (to be written)
** Local communities will be able to override the message so that it points to local documentation, if desired.
* This should be behind a feature flag so we can control the rollout and allow third party installations to disable this feature entirely.
* Possibly also limit this functionality to new-ish users (?), as seasoned editors will probably not enjoy it and will want a way to disable it. This may warrant a preference, but we should avoid that if possible.
**Related Tickets: **
* {T97063}
* {T288589}