custom field

Hello,
I am trying to understand custom fields settings when 'no' is checked under "Show During Quote Acceptance".
Where could these fields be used to collect information if not during the booking process? Where can I find an example of customer fields used in this fashion?

You might use this for recording data relevant to a property or booking that you got some other way - for instance, the door lock code of a manual lock on the property, so it can be included in emails you send to your guests, but you're the one that sets it.