Create a cache directory and make sure Mediawiki can write to it:

mkdir -p /disk2/wikicache

chown -R apache:apache /disk2/wikicache

chmod -R 777 /disk2/wikicache

Then enable file cache by adding the following lines to LocalSettings.php:

$wgUseFileCache = true;
$wgFileCacheDirectory = “/disk2/wikicache”;
$wgShowIPinHeader = false;
$wgUseGzip = false;

You can use tmpwatch to limit the size of cache on Linux.

Add the following line to LocalSettings.php to use iv skin as default skin.

$wgDefaultSkin = ‘iv’;

Create a custom namespace

To create a custom namespace, add a line containing your namespace(s) to LocalSettings.php, for example, to add a Patent and an Application namespaces:

$wgExtraNamespaces[100] = “Patent”;

$wgExtraNamespaces[101] = “Application”;

Ref: http://www.mediawiki.org/wiki/Manual:Using_custom_namespaces