Wikipedia:As of

Some articles have information that is valid only for a specific moment in history. If you suspect that the article will become significantly out of date in years to come, and want to ensure that people will update it, please include a link [[as of nnnn]], with year of validity. That way, it will be easy to find articles with possibly outdated information. More detailed tags are possible, and perhaps even sometimes desirable since all such pages can be located by checking "What links here" for this page. However, the year will generally be sufficient and is desirable for simplicity's sake. For more information, please visit Talk:As of 2003.

Paul A's talk page also has a useful statement on the usefulness of this page:

Hi Paul. I noticed in Blade Runner that you reverted 2003 back to as of 2003. I just wondered what the logic was, since the latter is a redirect to the former anyway. I'm not going to get into an edit war on something so minor, just curious. (Although as a Brit, the American usage grates a bit anyway) jimfbleak 06:38 21 May 2003 (UTC)

The reasoning, as it was explained to me when I asked someone else the same question, is that there is a fundamental difference between "In 2003, something happened" and "As of 2003, something was the case" - namely, that when 2004 rolls around all the former will still be true, but the latter will need updating. Making "as of 2003" a link means that, in years to come, it will be relatively easy to find pages that need updating by seeing what links to [[as of 2003 (http://www.wikipedia.org/w/wiki.phtml?title=Special:Whatlinkshere&target=As_of_2003)]]. (Just as, this year, one can find pages that need updating by seeing what links to as of 2002, as of 2001, etc.)

Each "as of x" page was made a redirect to the corresponding year page because the page needed to have some kind of content, and nobody could think of anything better at the time.

-- Paul A 09:16 21 May 2003 (UTC)