Q <overlordq <at> gmail.com> writes:
If you're referring to what rights a group is assigned, then no, there isn't a historical record. The only way, afaik, is possibly digging through the wikitech admin log and bugzilla and trying to piece it together.
The default user group rights are set in includes/DefaultSettings.php (or the relevant extensions) and their history can be recreated from SVN. Most default associations were never overridden (though those are the less interesting ones, I suppose). Important changes can usually be found in Bugzilla, under the Wikimedia/Site requests component. You could also try to check the page history of http://en.wikipedia.org/wiki/Wikipedia:User_access_levels .