(PARity file) A file that contains the computed parity bits from a source file. PAR files are generated from Usenet archives that have been broken into multiple files because of file size limitations ...

I want to do some very basic editing of STEP files, e.g.: I need to do this sort of thing about a hundred times, so I'd rather learn how to fish than pay someone to do it, even if it's only a few $$ ...