Reservation Fees for Indexers

I don't belong to the Editorial Freelancers Association, but I've seen other indexers mention it. In connection with a big but somewhat dubious project that would require setting aside some substantial time, I wondered about things that could go wrong.

I cover cancellation with less than two weeks notice and late payment in my contract. However, since it is possible that I would have to block out time for this project even before we get to the deposit stage (it's too convoluted to explain why), I was curious about the possibility of requesting a "hold" fee--which is the way I was thinking of it, the way some libraries talk about "holding" books (in academic circles it's usually putting them on reserve.

So I searched the EFA and found the following useful information.

"Reservation Fees. Another way to deal with the possibility that a project will be delivered late or will be canceled is to negotiate a reservation fee, essentially an advance to reserve the freelancer's time. A freelancer who agrees to set aside a lengthy period for a long-term project or who commits to a project well in advance may require partial prepayment."