|Subject namespaces||Talk namespaces|
|2302||Gadget definition||Gadget definition talk||2303|
|Current list (API call)|
A Wikipedia namespace is a set of Wikipedia pages whose names begin with a particular reserved word recognized by the MediaWiki software (followed by a colon). For example, in the user namespace all titles begin with the prefix User:. In the case of the article (or main) namespace, in which encyclopedia articles appear, the reserved word and colon are absent. (Note: main space articles can optionally include a colon at the beginning with no reserved word, so
[[:Article]] are equivalent. This is usually only necessary for the advanced technique of transcluding a main space article into a page in another namespace.)
Wikipedia has 30 current namespaces: 14 subject namespaces, 14 corresponding talk namespaces, and 2 virtual namespaces. These are all listed in the box to the right. While surfing Wikipedia, a list of namespaces is available in two clicks: do an empty search, then click Advanced under the search box. The list also makes itself available where needed in the dropdown menus of, for example, Special:Prefixindex, Special:Allpages, Special:Recentchanges, and Special:Contributions.
The aliases WP for Wikipedia, and WT for Wikipedia talk, work for page names in the search box, and making links as well as inclusions. See Aliases below for other aliases. (The pseudo-namespaces such as H for Help, and CAT for Category, are extremely limited. See Pseudo-namespaces below.)
The table on the right shows what number to use when you want to hide pages that are on your watchlist. See: Wikipedia:Hide Pages in Watchlist for details.
Previously, the Topic namespace was available for the Flow project but it has since been turned off on this wiki.