This is a follow up on my last post.
In order to find out if the phone will support the system message.
Go into LD 11.
REQ: IDU (XXXX) X's=TN number
<enter>
Should have info on the set itself and if the spot that says
RLS CODE: (1,2,3,or 4) is less than a 2,
then the display will not show the message, just replace with a newer phone as per Nortellian.