Reverse Polish notation (RPN), also known as Polish postfix notation or simply postfix notation, is a mathematical notation in which operators follow their operands, in contrast to Polish notation (PN), in which operators precede their operands.
The initials RPN may refer to: Registered Practical Nurse, also referred to as a licensed practical nurse. Radio Philippines Network, Channel 9, Philippines. Registered Parameter Number, as used in Musical Instrument Digital Interface synthesizers. Registered Psychiatric Nurse.