You can enable wait lists to allow participants to sign up for a waitl
ist once the group has reached its capacity.
In the
Group setup page, select the
Allow waitlist registrations when capacity is
reached checkbox.
Click
Customize waitlist policy.
Enter your customized message.
Save your changes.
Note: If you disable a wait list, then signing up for a wait list is
disabled, but the people who has already signed up for the wait list remains on
the wait list.