Under Windows or MacOSX, the VNM has a special feature allowing the various applications to keep the same CopperLan identity between sessions.

An application identity is relating to its Root Device, brand and model; several instances of the same application will differ by their Duplicate Number.

While it is obvious to store and recall a duplicate number in an embedded application, it is not the case for multiple software application running on computers... When launching a program multiple times on several (networked) computers, one expects being able restoring all connections correctly. This can be done only if each instance of that application is identified with the appropriate Duplicate Number.

To make this possible, the VNM stores a Duplicate Number relating to each instance of a specific application's identity.

When an application's Root Device is declared on the network with a blank Duplicate Number, the VNM in charge checks if its identity is known in the Duplicate Number Repository.

If not, a random Duplicate Number value (not conflicting with other devices of the same type on the network) is assigned and stored as the 1st instance Duplicate for such application.
If yes, the VNM checks if a Duplicate value is present for the instance number of the application on this computer, then
- If yes, it restores it
- If not, it creates a new duplicate as explained hereabove.

Practically, launching 3 instances of an application after it's been started in a previous session by at least as many instances, each instance will be reassigned the previously defined Duplicate Number in the same order they were initially created.