Default value: OFF.
This setting is only relevant if the setting BOOKING / PAYER_SHOW_SELECT is ON.
ON:
When making a booking it is mandatory to choose values in the fields payer and meeting type, other than ‘Payer' and 'Meeting type' when the total price is larger than 0 (zero).
OFF:
It is not mandatory to choose a value from the fields ‘Payer’ and 'Meeting type'.