If an attendee logs into a meeting and is then called into an audio conference, the two entries are automatically merged and only one name appears for the user. But if the attendee’s phone number is not recognized, the attendee may appear twice on the list, once under Acrobat Connect Professional with a name and once under Unknown Dial In without a name. If a host knows that an attendee is listed twice, the host can use the Merge Caller ID feature to combine the listings into one.