reservatio
Reservatio is a Latin noun meaning “keeping back” or the act of reserving. In modern usage, the term appears in English and in several Romance languages as the root of words such as reservation (English), reserva (Spanish, Portuguese), réserve (French), and riserva (Italian). The core sense is to set aside something for future use or to withhold it temporarily.
In law and contracts, a reservation denotes a proviso or clause that preserves certain rights or qualifications
In international law, reservations to treaties are statements by a state at the time of signing or
In everyday usage, reservation also refers to the act of booking or holding a place or service