The July 2006 version of the ENIGMA Control List, number 22, is now current. It has been distributed in a pdf file, making it somewhat easier to read.
This list has all those "numbers" station identifiers that have become the standard means of referring to the otherwise chaotic broadcasts on the HF band. They've done a great job of classifying everything, so we don't have to, and using their official list means that everyone in the world knows what everyone else is saying. There is definitely less confusion in this end of the hobby since these Control Lists became standard.
Number 22 replaces previous lists, and should be considered the official reference for numbers designators until it too is superseded. As always, the Control List remains the intellectual property of ENIGMA2000, and used by Utility World in its entirety exactly as it came from the current online incarnation of the European Numbers Intelligence Gathering and Monitoring Association. These are the terms by which permission for its use is given, and also it is the only way to do it which will not propagate errors through the Internet for years to come. Please do not post altered or incomplete versions of this list, or mirror it without asking ENIGMA2000.
And, with that out of the way, here's the link.