D-Link VoiceCenter DVX-2000MS User Manual page 29

Section  - Installation
On the Identification tab, in the User Type box, select Person from the drop
down menu if it is not already selected.
In the Name boxes, type the first and last name, and optional nicknames or titles
of the person who will use this phone. You should specify nicknames and titles if
you think callers will use when asking for this user.
In the Extension number box, change the extension number if desired and click
OK to continue.
Click OK
You have now assigned the person's name to Line 1 with the extension
number you specified. You can assign up to 3 additional users to this phone
or click Next to continue.
Click Next
D-Link DVX-000MS User Manual