In HTML and XML referring to articles in the GFDL text corpus, a standard wiki URI is stated as follows:
Only the "/wiki/" is constant. Although they are a little more complex than the interwiki link standard that applies when both protocol (http://) and subprotocol (/wiki/) can be assumed, these are relatively easy to remember, e.g. one can easily rattle off URIs of the form http://en.wikipedia.org/wiki/troll where only troll must change to find some other article within en.wikipedia, and where one would be able to simply swap consumerium for wikipedia to find the equivalent article there, i.e. http://en.consumerium.org/wiki/troll. If no article in that language at that service exists, then an explanatory message in the requested language should appear to offer perhaps a machine-translated page, or approved references elsewhere.
Supporting this standard radically simplifies wiki linking for the average user and lets different web services compete to support the GFDL text corpus better. Unfortunately neither MediaWiki nor GetWiki imposes them as a default. They really should.