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: To a century: This is a redirect from a year or decade to the associated century article. Years from 4000 to 1700 BC should redirect to the relevant century per Wikipedia:Timeline standards. Do not replace these redirected links with a link directly to the target page. Individual articles may be created for these years or decades in the future. 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: