From Envirowiki

Special pages are pages that are created by the software on demand. They are located in their own namespace Special: and are not editable directly as other pages.

Some special pages depend on the preferences that have been set by a user, e.g. the number of titles which is displayed on a user's watchlist.

[edit] 1 List of special pages

Clicking the link Special:Specialpages will take you to a list of all special pages on a wiki. Such a link is often accessible in the toolbox on the left hand panel.

[edit] 2 External links

Also on Mediawiki Meta: pages http://meta.wikimedia.org/wiki/Help:Special pages