iCalendar RFC 2445
When normatively referencing RFC 2445 on this wiki, either do so by linking to this page with:
or directly to http://tools.ietf.org/html/rfc2445.
Avoid linking to the informative HTML translation of rfc2445.txt, which you must explicitly do by avoiding simply using the string RFC 2445 in your text, as MediaWiki appears to auto-hyperlink it to the HTML translation thus: RFC 2445.
vCalendar, sometimes referred to as "iCal 1.0", or vCal.