http://www.mediawiki.org/wiki/Manual:$wgProxyKey says "This feature
has been deprecated and should not be used with current versions of
MediaWiki. This feature was deprecated in version 1.4.0."
However, go install fresh MediaWiki from scratch. There $wgProxyKey
is. hardwired right in LocalSettings.php "sticking right in the users'
face with no documentation".
Version: unspecified
Severity: trivial