If you follow the link, it points to a project page about the use of "as of..." links.  Basically, you try to keep article pages from being date-sensitive; however, when this is unavoidable, you attach a link whose target is as of yyyy, where yyyy is a year.  This helps people to keep track of the pages which may expire so that they can keep them up to date.  Please see Wikipedia:as of and Wikipedia:Avoid statements that will date quickly for more information about these topics. —  03:02, 20 Jun 2005 (UTC)