Turn off pdf receipt for free registrations
Turn off pdf receipts when emailing a registration confirmation for a free ticket.
Karen Bethell commented
seems like a simple enough option - a email confirming the ticket/registration you purchased with the details of the event seems like a brilliant idea. Opt in or out of sending an official receipt. Even a $0 receipt is a little misleading. Not always prepared to know the benefit portion of the ticket purchase prior to the event...