Category:Pages with ignored display titles
From Inkipedia, the Splatoon wiki

Even if it appears unused, this category should not be deleted.
Reason: Auto-category per MediaWiki:Restricted-displaytitle-ignored
Pages where {{DISPLAYTITLE}} is used with an invalid value.
DISPLAYTITLE may only format the current page's title header. The value must be equivalent to the default title: only capitalization changes to certain parts of the title (not all) and replacing spaces with underscores are allowed.
This category is an auto-category per MediaWiki:Restricted-displaytitle-ignored. The warning shown on invalid usage is MediaWiki:Restricted-displaytitle.
For more information, please see the MediaWiki wiki page.
Pages in category "Pages with ignored display titles"
The following 4 pages are in this category, out of 4 total.