Ah..yes.. an Entity must have identity. I should have remembered this since I discuss it in my Domain Driven Design presentations.
>from Wikipedia: An entity may be defined as a thing which is recognized as being capable of an independent existence and which can be uniquely identified.
>see more here
http://en.wikipedia.org/wiki/Entity-relationship_model
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer