The system does not really provide a waiting list, but you can use the "Registration of Prospective Participants" (registration of people who are interested in the event) for such a requirement, if you do not use that already for other purposes.
1. First, please go to:
Overview => Settings => Conference Phases and Deadlines
... and disable the registration of new users and the registration of participants (both!), so people can neither register as users nor as participants for your conference any more.
2. Next, continue on this page:
Overview => Settings => Settings for Users Registration and User Options => Registration of Prospective Participants
Enable the option "Enable Prospective Participant Form", which will activate the registration link for prospective participants on the log-in page.
Set the option "Reveal Account Data" to "No" if you do not want to send them the log-in details with their confirmation e-mail.
Please also enter an URL to which users will be returned after submitting their registration (see image).
3. Adapt the Wordings and Phrases according to your requirements:
Overview => Settings => Wordings and Phrases
A) Search for "REGISTER_PROSPECT" to convert the wording of the registration form to a waiting list.
To update the link on the login page, please search for "REGISTERPROSPECT".
Example:
"Please register below to get the latest news on "%1". Your data will be treated confidentially and not be used for other purposes." has to be changed to
"Please enter your details below to enroll for the waiting list for "%1". We will contact you if a space becomes available. This enrollment is not binding.
Your data will be treated confidentially and not be used for other purposes."
B) Search for "EMAIL_PROSPECT" to update the wordings for the e-mails sent to the participants.
Please test your settings by carrying out some sample registrations.