In ld 20, print all the dn of the ACDDNs that you printed in ld 23. The DNB will just show the DN if no agents are assigned to this number. If there are agents assigned to a DNB it will display the position ID and the TN of each agent. You can then print a tnd of the tn to see how and for what it's used.
most likely some or all of them will be for your voice mail
Also, There is another Forum that you should use. It is under Wire Closet - Nortel-Meridian Systems