Manual:$wgWhitelistRead

Details
If a group of users is blocked from viewing the wiki by using the $wgGroupPermissions setting... ...you may still want them to be able to view certain key pages, in particular the login page! This setting holds an array of page names that all users are allowed to view, regardless of their group permissions.

A recommended minimum which allows everyone to view the home page and the login screen is as follows:


 * until 1.16.x


 * starting with 1.17.0


 * starting with 1.18.0


 * starting with 1.18.1

Example
Anonymous users can only view Special:Userlogin

Anonymous users cannot read or edit any other page, but can still create accounts: To additionally block account creation by anonymous users, add the following line: With anonymous account creation disabled, sysops will need to create accounts for new users manually (or a LDAP extension is used for authentication)