Manual:$wgHiddenPrefs

Details
  is an array to disable certain pref>Special:MyLanguage/Help:Preferences|user preferences (preferences system was rewritten in 1.16).

This obsoletes   with the following code:

For a list of preference names and what they do, see pref>Special:MyLanguage/Manual:$wgDefaultUserOptions#Available_preferences|Manual:$wgDefaultUserOptions#Available_preferences.