Hi all,
we propose to remove `capitalize-all-nouns` skin functionality from MediaWiki core without deprecation in 1.37.

Patch to remove: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/435638
Patch to continue functionality in Monobook: 
Bug: https://phabricator.wikimedia.org/T97892
Existing uses: https://codesearch.wmflabs.org/search/?q=MagicWord%3A%3AclearCache&i=nope&files=&repos=

MediaWiki core has a feature whereby the setting $capitalizeAllNouns = true can be set in a LanguageXx.php file. When this is set, OutputPage attaches the `capitalize-all-nouns` CSS class to the page <body> element. The only languages for which $capitalizeAllNouns = true are German and languages with German as a fallback (e.g. Alemannic).
The only widely used skin using this has been Monobook to disable lowercase transformation of tab titles for those languages. A few other skins might have applied the same functionality when basing on top of Monobook.
We've copied this obscure functionality over to Monobook in the meantime and would recommend doing so for your skin if you like to continue to use it.
In any case, as this removal results in a non-existing CSS class mostly rendering of some elements of the skin in some languages would change slightly.
Please note, that no other modern Wikimedia deployed skin has used this ever since Monobook.

Thanks to volunteer Jack Phoenix and my colleague Jon Robson for driving this work.

Regards,
Volker