This is a stab at describing a separately implementable part of the smart producer ideas. It might be useful alone or it may not be of much use until the smart producer is here.

The idea may be viewed as an extension of the space bank architecture. The guarded bank is controlled by a key whose dissemination is too gross a way to manage storage reclamation. I think that these ideas can be introduced outside the bank logic.

The smart producer design adopts the familiar structure of classical directories upon which to hang the accountability concept {(spd-def)}.