Messages and Message boxes are used in various places and should be part of M101
Current status quo
| MediaWiki core | mediawiki.UI | OOjs UI |
| -- | -- | --
| {F3372655 size=full} |{F4530216 size=full} | {F4468719 size=full} {F4491169} |
**PostEdit messages**
{F7451633}
**MobileFrontend**
{F4669690 width=640}
**Special:UploadWizard**
{F4669345 size=full}
Editing a disambiguation page on English Wikipedia, with an `fmbox-editnotice` on top and anonymous user edit warning with class `.warningbox` (core messages) below
{F5243825 size=full}
In core there are several classes being used:
.warningbox
.mw-warning e.g. https://en.wikipedia.org/w/index.php?diff=666058337&oldid=666058325&useskin=vector
{F10812421}
.mw-warning-with-logexcerpt (seems to be used on Special:MovePage and LogEventsList
**Collections extension**
{F8223130 size=full}
Scope of this task are the visual aspects of message boxes.
Finding guidelines on #voice_tone is important as well, but are not part of this task here.