Using MediaWiki Variables/Page name

A page name variable is one that expands to the name of a page or parts of a page name.

Every wiki page you visit belongs to a specific namespace. expands to the namespace of the page you are currently viewing. When you view a page in the main namespace the variable expands to nothing (e.g: "") because the main namespace does not have a name. Try previewing a page in each namespace with added. What do you see?