ref: 828c577e03e15f59a69bff965893e3a670a8f10f
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.