Category:$1

This category is sometimes used indirectly to categorize some translated messages with a "$1" placeholder parameter (that will be replaced by an actual category name when these messages will be used).

It may also be used for tracking errors in template usages. In some source messages (in English) this may be an incorrect syntax for the link to a variable category (missing colon after the double opening brackets): trying to fix it in translations makes the translation fuzzy, removing it from all translations make translations incorrect just like the source. For now Translatewiki.net still thinks that such wikisyntax is a valid link to a wikipage that should be kept in translations, but it does not recognize the special namespaces "Category" and "File" (or "Image"), whose syntax for linking to them (rather than performing a special action or rendering) is different from regular namespaces.

Signal these errors to source project maintainers.