To configure the sub-block to take in attendees without credit cards, go to your sub-block profile and scroll down on the "Admin" tab to the "Sub-block Billing Options" header.
Here you'll specify whether the block will require credit cards.
Next, you'll enter your number of free nights. The number entered in this field will determine how many nights an attendee is allowed to add to their booking before the system requires them to provide a credit card and pay for the booking. As an example, if you enter four nights like in the above screenshot, your attendees won't have to add a credit card to their booking unless their booking goes over four room nights in length.
When your attendees book a stay that's longer than the entered number of free nights, the system will require them to enter a credit card to proceed, and the reservation total will be that of all room nights, not the difference between the number of free nights and the number of nights on their booking. It's an all or nothing setup; if your attendee adds more than the free amount, they pay for the whole reservation.
Hotel Billing Instructions (Payment Note Text)
In the Hotel Billing Instructions field, you can enter text that will display as the Payment Note for bookings made without a credit card. Again, the default text is "Payment Information is not required", but you can change this to anything you want, such as a master account number the hotel should bill to, by adding the text in this field.
That's it! Once you've filled out the fields, if your attendees in this block book a room that's equal to or less than the provided number of free nights, they won't have to enter a credit card and can book freely!