PN

Arts and entertainmentEdit

Pacific National, a rail freight company in Australia
Participatory notes, issued to unregistered overseas investors in Indian stock markets
Pennsylvania Northeastern Railroad (reporting mark PN)
Promissory note, a contract where one party makes an unconditional promise in writing to pay a sum of money to another
West Air (China) (IATA airline code PN)

Path graph of size <math>n</math>, denoted by <math>P_n</math>
Petri net, one of several mathematical modeling languages for the description of distributed systems
Polish notation, a prefix notation proposed by Jan Łukasiewicz
Polynomial vector spaces, denoted by <math>\mathbb{P}_n</math>
Pseudorandom number sequence

Part number, an identifier of a particular part design used in a particular industry
Particle number, in air-quality measurement
petanewton, a quadrillion newtons
Planetary nebula, in astronomy
Post-Newtonian expansion, an approximation of General Relativity
Proportional navigation, a concept in missile guidance systems
Pseudorandom noise, a deterministic sequence of pulses used in spread spectrum communication and rangefinding
Phosphorus mononitride (PN), an inorganic compound found in space