Mutt,
Thank you for your helpful answer. The AFM states;
The airplane ATC Data Link system has been demonstrated to comply with the applicable safety, performance and interoperability requirements of EUROCAE ED-120 (incl. change 1 and 2), ED-110B and the Commission Regulation (EC) No 29/2009, for continental ATN-B1 Data Link using VDL M2. The airplane ATC Data Link system does support multifrequency operation as defined in ARINC Spec. 631-5.
I will check what is registered with the white list as our CAMO have done it for us.
MM