ref: cd310e419c092435be07e5ff9d89c6151b8d5df9
dir: /sys/src/cmd/postscript/postreverse/README/
A simple program that reverses the pages in PostScript files that conform to Adobe's Version 1.0 or Version 2.0 file structuring conventions. postrevese also handles a small class of files that violate page independence (eg. output from dpost) and can be used with all the translators in this package. The output can be conforming even if the input file wasn't.