2010/9/23 Brion Vibber <brion(a)pobox.com>om>:
(If using memcached, be sure to clear those out,
reinitialize, or otherwise
do something that forces old values to be cleared or ignored.)
$wgCacheEpoch is a good one for this. The easiest way to change it is
to touch LocalSettings.php.
Roan Kattouw (Catrope)