To a section: This is a redirect from a topic that does not have its own page to a section of a page on the subject. For redirects to embedded anchors on a page, use {{R to anchor}}instead.
From a shortcut: This is a redirect from a shortcut in any namespace to a page in any namespace.
Shortcuts are wikilinked on community pages, talk pages, and edit summaries, but not in mainspace articles.
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.
