Provide pool

Allow a pool of items (which may contain a single item) to be bought or given away.

Related items
This concept is a subclass of the following concepts:
 * is a subclass of::Exchange

This concept is found in the following software:
 * is found in::TOIA AMS v1.0
 * is found in::TOIA Web Service v1.0
 * is found in::WebCT
 * is found in::e3an Web Service v1.0