When used with the "Redirect category shell" (Rcat shell) template:

This page is a redirect. The following categories are used to track and monitor this redirect: From a subpage: This is a redirect from a subpage. In a page title, a subpage name appears after a forward slash (/); for example, "Wikipedia:WikiProject Cricket/Articles", which is a subpage of "Wikipedia:WikiProject Cricket", redirects to Template:CricketRecentChanges. Not all articles or other pages with "/" in their titles are subpages (e.g. CP/M). If this redirect is in mainspace, then it will populate the Redirects with old history category bold-linked above; if in any other namespace, then Category:Redirects from subpages will be populated. When appropriate, protection levels are automatically sensed, described and categorized.

Template {{Redirect category shell}} may be used to add one or more rcat templates, along with their parameters and categories, to a redirect. For more information see the documentation page below.

When used by itself: