Macro with several entry screens
One of the situations in which you might have several entry screens in the same macro is when a host application begins with a series of application screens one after another, such as application screen A, followed by application screen B, followed by application screen C. For instance, screen A might be a logon screen, screen B a screen that starts several supporting processes, and screen C the first actual screen of the application.
In this situation, you might want the user to be able to run the macro whether the user was at application screen A, B, or C.