What does pnx stand for?

Pneumothorax - Medicine (AD)

Imperial Airways, Inc. - ICAO designator (FAAC)

Phong-Kniang - Language code (ETLW)

Pneumothorax - Medicine

Portsmouth Naval Shipyard - Federal Railroad Administration identification code

Precincts - Telegraphy (PCTE)

Private Network Exchange - Computer science (VLIE)