Hidden Namespace
Appearance
Introduction
Unlisted would probably be a better name, but I implemented a way for pages to not show up in searches. These pages are not inaccessible but can only be accessible with a direct link. To do so, you create a page with the namespace hidden in front of it. Easiest way to do so is go to your user page and add to your page Hidden:Page_Name replacing Page_Name with the name of your page, and save it. Your user page is easy to get to, especially if you made an edit to a page, so if you're concern about people getting to your hidden page through your user page, you can remove the link to your hidden page afterwards.
Configuration
Code added to the LocalSettings.php was the following:
define("NS_HIDDEN",3000);
define("NS_HIDDEN_TALK",3001);
$wgExtraNamespaces[NS_HIDDEN] = "Hidden";
$wgExtraNamespaces[NS_HIDDEN_TALK] = "Hidden_talk";
$wgNamespacesToBeSearchedDefault[NS_HIDDEN] = false;
$wgNamespacesToBeSearchedDefault[NS_HIDDEN] = false;