Translations:Help:Tracking categories/2/en

What category to use is determined by the tracking category's system message, that is, a page in MediaWiki namespace. If the message is a single hyphen-minus (-), then the tracking category is disabled. Often wiki admins mark such categories as hidden (using the $2 magic word), since they are meant for maintenance and not general consumption. Some sites use $3 to modify which category is used based on namespace, but that doesn't work properly until 1.19.