In reply to owensum:
Only thing I know about it is that when we stopped off for a quick look on the way to The Alps in 1971, because we then climbed a lot on South East sandstone and were interested because someone had told us that the Fontainebleau crags were laid down under the same ancient sea and therefore connected with Harrison's, Bowles etc, the place was known to the locals as ''Bleau" and they were therefore Bleausards.
Quite when it came to be known by the, to my mind, for less romantic sounding Font I know not. Do they now refer to themselves as Fontards? Sounds like a term of abuse.