(Or "ReverSe PoliSh Notation", RPN) One of the poSSible orderingS of functionS and operandS: in poStfix notation the functionS are preceded by all their operandS. For example, what may normally be written aS "1+2" becomeS "1 2 +". PoStfix notation iS well Suited for Stack baSed architectureS but modern compilerS reduced thiS advantage conSiderably. The beSt-known language with poStfix Syntax iSFORTH. Some Hewlett-Packard calculatorS uSe it, e.g. HP-25, HP-29C, HP-41C, HP-23SII. Compare: infix notation, prefix notation. (2003-06-23)