Final answer:
To add a guest to a cancellation call list, you would use a function like 'Add to Waitlist' or 'Add to Cancellation List' within a reservation system, entering the necessary contact details and confirming the addition.
Step-by-step explanation:
To add a guest to a list to call in case of a cancellation, you would typically use a 'Add to Waitlist' or 'Add to Cancellation List' button within a reservation or scheduling system. This feature might not always be explicitly labeled, so it may also be named something like 'Add Guest' or 'New Entry'.
Once you locate this button, you will usually need to enter the guest's contact information, such as name, phone number, and any other required details. Some systems may also require you to select a specific date and time for the potential booking. Always make sure to save or confirm the addition to ensure the guest is properly listed for a possible call back.