NORD removed its ME page. If you do type in Myalgic Encephalomyelitis, only a list of patient organizations pops up.
Well, ME isn't rare as arguably there are more than a million worldwide that meet the ICC and now there is ME/CFS so I guess they figure they won't have a page anymore. But, it was another resource people could go to and they also referenced the 1969 WHO classification as a neurological disease on this page.
FYI - This is the 1969 WHO classification information. International Classification of Diseases. I World Health Organization. 1969. pp. 158, (vol 2, pp. 173).