From: Michael Bernstein [mailto:mbernstein@profitscape.net]
It would be very beneficial to be able to 'point' to arbitrary objects as if they were sub objects, thus enabling one-to-many, many-to-one, and many-to-many relationships not constrained by the object heirarchy.
Classic example: Many author objects, many book objects. Authors can have written several books, and certain books are collaborations with more than one author. It does not make sense for books to be contained within authors, or authors to be contained within books.
While this simplistic scenario would allow us to either assign a list property with book titles to an author object, or a list property containing authors names to a book object, and live with the small amount of duplicated data
I think the key observation here is that the additional information should be sufficient to identify the foreign object.... then the pointed-to object can be located by searching a Catalog.