Based on T110604#2515527
**Necessary things are:**
* Notification name
* A screenshot
* which kind of notification it is (notice or alert)
* what triggers that notification
* what is received by user:
** Primary information (first link)
** Secondary information (second link)
** Details (what's at the bottom of that notification
You can find inspiration in https://www.mediawiki.org/wiki/Help:Notifications/Notifications_types
**Integration:**
* If that new notification is used on all WMF wikis as a "core" extension (like "Thanks" extension is), it can be integrated in the //Default notifications// section.
* If that new notification is used on some WMF wikis as an optional extension or Beta feature, it can be integrated in the //Notifications from optional extensions// section.
** If an extension tested as a Beta feature or active only on certain wikis changes something on a //Default notifications//, it can be documented on the //Default notifications// section, as a separated paragraph, with all necessary details.
* If that new notification is not used on WMF wikis, it have to be on a separate page, with all user documentation for the extension to avoid. A link can be created from the notifications type page to that documentation.
All this is open to comments. I'll then create an Help page on mw.org.