What is "Rule 62", and where did it come from?

From "Not God" by Ernest Kurtz:

"Some time in early 1940, the program succeeded in sobering up an alcoholic possessed by a promotional drive even greater than [Bill] Wilson's.  This worthy, in his enthusiasm, drew up comprehensive plans for three separate corporations to spread the message -- a club, a clinic, and a loan office.  He submitted his blueprint, outlined in 61 rules, regulations and by-laws, to AA's New York Headquarters."

Bill Wilson replied that even less grand schemes had failed in the past, but that the man's group was autonomous, and had the right to igneore the warnings.  It did, and the result was as expected, disastrous.

The man wrote again to New York, basically saying, "You were right and I was wrong", but with it he enclosed a card which he had already mailed to every AA group in the US.  Designed and folded like a golf score card, it had printed on the outside:  "Group  ________ - Alcoholics Anonymous:  Rule Number 62".  When the card was opened, a single sentence met the eye:

"Don't take yourself too damned seriously"

Ducmom, Spirituality of Imperfection was also written by Ernest Kurtz.