As part of the Unified Community Platform project, this wiki and 38 others will be migrated to the new platform in the next few weeks. Minimal changes are expected as part of this migration. Read more here.
Help:Protecting and unprotecting pages
Protecting and unprotecting pages is very straightforward, but these operations require sysop permissions.
You can designate a page as a protected page by clicking protect in the drop down tab, and supplying a comment (a brief textual description of why you are protecting the page).
There are several reasons why a particular page might be protected. See Help:Protected pages.