3.10. Whiteboard 
Whiteboard allows you to work together with other call participants by typing
notes, drawing or importing images on a blank page during a conference call.
INFO:
Only UC users are allowed to start the whiteboard during a conference call.
Guest participants can use the whiteboard functionality, but they are not
allowed to start it.
The following UC clients support the whiteboard functionality: WebClient, UC
Desktop App and Fusion for Office.
‣ Parent topic: Section 3. WebClient Features