I agree with you, TEd R. Been ages since I heard the term. My recollection is that a contonment was an area set apart in a larger area for use by a special group. For instance : on a permanent military base - and area of a couple of buildings, mess hall etc., for use by Special Forces which are technically part of the whole but in a practical sense operate as a separate unit.
I've also heard it used to mean a separate area for combatants, totally self-sufficient - set up within or abuting a larger, less organized area usually of civilians.
When we were stationed in the Philippines (1967-68) there were a number of off-base housing areas owned by Philippinos which were approved for occupation (rental housing) by the military. They were often called cantonments. Now, they are all covered in ashes from the eruption of Pinatubo, or so I am advised.
