Artefact:Model/org/oomodels/sandbox/business/foundation/entities/management/Contact

Code
> CoreObject
 * Contact
 * Entity org/oomodels/sandbox/business/foundation/entities/Entity
 * Tasks org/oomodels/sandbox/business/foundation/work/Task(*:*)
 * Log org/oomodels/sandbox/business/foundation/work/Log
 * Notelets Notelet(*:*)
 * Worklets Worklet(*:*)
 * Groups Group(*.*)

Things like Task, Log, Work/Notelet obviously can be attached to many business objects, if not to all. So a superclass "business object" might be introduced to handle this.

Alternatively, a superclass "Core" with "Accessories" of arbitrary types could be introduced here to allow attachment of those things as well as many more. This approach would be extensible and has been proven valuable in other contexts.