A namespace is a special predefined prefix attached to an article title, indicating that the information in the article should be distinguished in some way from the main (non-prefixed) article of the same name. (Example: California is an ordinary article; Talk:California is for discussing that article; Category:California is for using that title as a category for other articles.) Articles with namespaces other than main do not appear in search results unless they are searched for explicitly from the search page. dKosopedia currently has sixteen namespaces: the main (non-prefixed) namespace; User:, dKosopedia:, Image:, MediaWiki:, Template:, Help:, Category:; and their associated discussion spaces (e.g., Talk:, User_talk:, DKosopedia_talk:, etc.)
Namespaces other than main can be accessed by prefixing the namespace and a colon to the article name. However, custom namespaces cannot be created by adding a colon to a prefix that isn't already a predefined namespace. New custom namespaces can only be created by editing dKosopedia's configuration files on the server.
A number of custom namespaces have been proposed for dKosopedia, including Tag, Position, FrameShop, etc. However, none of these custom namespaces have (yet) been implemented on dKosopedia; attemping to use them in an article title results in an ordinary article in the main namespace.