Help:Tracking categories

Tracking categories are a feature of MediaWiki that allows pages with certain characteristics to be tracked. It works by adding any such page to a category automatically.

What category to use is determined by the tracking category's 1>m:Help:System message|system message (i.e. a page in MediaWiki namespace). If the message is a single dash (-), then the tracking category is disabled. Often such categories are marked as hidden ( __HIDDENCAT__ ) as they are meant for maintenance and not general consumption. Some sites use 3>Extension:Parser functions|Parser functions to modify which category is used based on namespace, but that doesn't work properly until 1.19.

Extensions can also add new tracking categories (via Parser::addTrackingCategory method).

Some wikis add other sort of tracking categories via some hacks, for instance itwiki1>w:it:Categoria:Pagine con errori nelle espressioni|this category which tracks pages with  #expr  errors, added through the itwiki2>w:it:Special:PrefixIndex/MediaWiki:Pfunc expr|relevant errors shown on such pages.