Elements with Duplicate Names
Overview
If you try to add a model element (or rename a model element) and another model element of the same underlying type exists anywhere else in the model, Rhapsody displays a warning. For example if you have a Block named B in a package and you try to add another Block (or an Interface Block, Flow Specification and so on which have the same underlying type) into another package with the name B then Rhapsody displays a warning:

Whilst this is very useful - it can be disabled by setting the following property at project level:
General.Model.WarnForDuplicates
Note that in some older versions of Rhapsody, trying to add a new model element (with a duplicate name) via the API without this property set would fail badly - since there is no way for the API to respond to a warning dialog! Thankfully in more recent versions this is not the case adding elements with duplicate names through the API ignores that property and adds them anyway.