Do not delete this category, even if it appears unused.
Reason: "This is a maintenance category and may be empty at times."

This category contains pages that have a cargo query and thus might need to be purged after every edit. Editors should be informed about this, which is why these pages should get a MediaWiki edit notice. Create a new page MediaWiki:Editnotice-0-<page name> and only put {{purge cargo|box=y}} as its content. That will remove the page from this category.