Exhibition (may share "superclass" with Collection) - has a host of annotations along with some core info. Associated to objects. Exhibit has temporal quality (when it was on display). Will have Location association (with temporality) for a traveling exhibit. Object association may have temporal quality, or Exhibition association may be to a qualified Exhibition/Location/time-period instance. Some objects may only be in an exhibit for a while, because of damage/theft/other concerns.
Note that the CollectionObjectentity is inherently hierarchical, and so Exhibition may just be a CollectionObject that is formally marked, and that may have some additional information. Need to clarify which aspects of the Exhibition entity are not covered by CollectionObject capabilities - we want to minimize duplication. Unlike a Collection, an Exhibition has a temporal aspect of when it was active (although the information remains). An Exhibition has some notion of state as well (actually, this is a better way to think of the temporal aspect), associated to the workflow of planning, travelling, on display (at some location), etc. In addition, an Exhibition is inherently more dynamic w.r.t. membership over time, since CollectionObjects may only be part of an exhibit for portions of its travels (due to conservation, insurance, or other constraints). We should be able to model most of this with some combination of workflow state, Movement (for travelling exhibits, and possibly for the local movement associated with display), Location (including local references as well as remote references for travelling exhibits), and Loan (to model travelling exhibits).