The object dependency information can also be used to select un-referenced objects that are not used by any other object. In our example, there are three un-referenced objects: pMainMenu, PlacedBy and vJunkVar. Un-referenced objects can be selected using the “u” selection criteria, as shown in the following example:

ZOMList +p u

Objects Found by Unreferenced Criteria “+p u”

Often, objects that are not referenced are no longer in use by the application and can be destroyed. This is not always the case as shown above where the unreferenced pMainMenu, which is the root of the dependency tree, is a very significant object to this application. Another object, the role PlacedBy, could have been created in the application as a convenience to users entering ad hoc queries.