How do I limit the number of attendees for an appointment?
For New Calendar users, the Scheduler tool is now optional. Please contact your Account Relationship Manager to enable it.
Note: Scheduler has already been enabled for those accounts that have been actively using it.
Click the appointment title.
Edit Appointment Details
Click Edit to edit appointment details.
Limit Number of Attendees
Type the number of attendees in the Limit this slot to # users field . You can edit the individual appointment description in the description field  if you desire. Click the Save Changes button .
View Individual Appointment
View the changes you have made.