Brion Vibber wrote:

These settings will be relevant to you:

# This is the list of preferred extensions for uploading files. Uploading # files with extensions not in this list will trigger a warning. $wgFileExtensions = array( 'png', 'jpg', 'jpeg', 'ogg' );

# If this is turned off, users may override the warning for files not # covered by $wgFileExtensions. $wgStrictFileExtensions = true;

Thanks Brion, that's what I was after. Strange that I couldn't find it on meta.

Regards,

Oliver