When the preselection procedure is over you will receive an e-mail from the Traineeship Office with the list of all the 'registering numbers' that passed the preselection. Bear in mind that when you apply, you receive automatically a registering number, which represents you in the communication flow with the Traineeship Office.
In case you passed the preselection (which is actually a filtering of the CVs), you enter automatically on a list with three persons for one place, meaning that you have 33% chances to be selected.
The key stands in the hands of the heads of units from the chosen Directorates or Services or from the cabinet responsible, in case you applied for cabinets.
You just have to be contacted by them in case your application raised their interest.
They can get in touch with you either by mail or calling.
If you were contacted by them it doesn't mean that you have been selected!
The final answer you'll get it again by mail!