.RP .TL A Reference Manual for the IRAF Subset Preprocessor Language .AU Douglas Tody .AI .K2 "" "" "*" January 1983 (revised September 1983) .AB The IRAF subset preprocessor language (SPP) implements a subset of the proposed full IRAF scientific programming language. This paper defines the language and gives several examples of procedures written in the language. The differences between the subset language and the full language are summarized. IRAF tasks or programs are discussed, and a working example of an IRAF program is shown. The XC compiler for the SPP language on the UNIX software development system is introduced. .AE