Reservation agreement (umowa rezerwacyjna)
An agreement with a developer that takes the chosen unit off the market for other people for a set time. It is often signed before the developer agreement, e.g. for the time you need to apply for a loan.
It is governed by the Developer Act: the agreement must be in writing and specify, among other things, the reservation period and the reservation fee, whose amount is capped by the Act. Before signing, the developer should give you the information prospectus.