Reverse Polish notation (RPN) is a mathematical notation in which every operator follows all of its operands, in contrast to Polish notation (PN), which puts the operator before its operands. It is also known as postfix notation.
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.