Your callback function is called before the file management event. It is called only for models that are the explicit objects of the file management operation. For example, it is not called when a part is saved as a result of saving a parent assembly.

If the Creo+ user initiated the event, the callback is called before the prompt asking the user for the name of the Creo+ models on which to act.

The callback function can optionally write output arguments that determine the Creo+ models on which the event will operate. In this case, Creo+ will not prompt the user.

The callback function can, by returning an error status, cancel the file management event altogether.