Friday, February 6, 2004 10:31 AM
A named object required both left and right hand side. Left hand side is the object identity (name), right hand side is it's type.
A Person object called John is represented
The underline denotes it is an object and not a class.
An anonymous object does not require a left hand identifier.
Any Person object is respresented
When showing interaction with a static method such as in an interaction diagram there is no unlerline.
These are the UML standard naming conventions.
Hope this is of help