Roi,

>>A phone business object could both apply the rule to any requests to update the back-end but also expose a GetMask() method that would return the mask to the front-end for UI implementation. The business object could either store the mask as a property or have a encapsulated method to retrieve it from the data dictionary. Would that work?

Do we really want that many (potentially costly perf-wise) COM or DCOM calls just to have an "ideal" design? BTW, I don't know the right answer. :-)