Tipsy
jquery.tipsy (a local fork of tipsy code) is in core, and more technically documented at ResourceLoader/Default_modules#jquery.tipsy. It has been deprecated since MediaWiki 1.28.
The default code is given Agora appearance and behavior (as specified in mockups like https://trello.com/c/vr0Oai8G) via [?these additional components?].
See also
[edit]- task T117720: Remove use of jquery.tipsy from Wikimedia-maintained code
- task T336019: jquery.tipsy will be removed from MediaWiki core.
- OOUI/Widgets/Popups