The text for 'content-model-proofread-page' is currently "Page: page". This is extremely difficult to parse (I think it's supposed to mean "a page in the 'Page:' namespace") and it gets even worse after translation (the qqq docs do not explain what it's supposed to mean, and translators are having a hard time guessing).
(The text is shown on "Special:ChangeContentModel/Foo" in the dropdown, next to clearly named items like "wikitext", "plain text" or "JavaScript".)
URL: https://translatewiki.net/wiki/MediaWiki:Content-model-proofread-page/pl