QUESTION AND ANSWER
Why is there a 'Caller01' in my Attendee List?
The Unidentified Caller feature shows a 'Caller01'in the Attendee List when an attendee has joined the software and dialed into the conference without entering their Audio Pin.Once the Attendee enters their Audio Pin, the Caller01 in the Attendee List will be removed.
The Unidentified Caller feature can be enabled or disabled for the entire account by the Company Admin (This feature cannot be turned on/off on the Organizer level)
This feature will be enabled by default for all new accounts.
Additional info here: http://support.citrixonline.com/en_US/Meeting/all_files/G2M090067
To enable or disable this feature, see https://goo.gl/QzQIKv