PostScript Printer Description
From Just Solve the File Format Problem
PostScript Printer Description (PPD) files describe the capabilities of a printer (paper size, etc).
I mean, sure, the Internet Printing Protocol also describes this, but apparently printers need to describe themselves in both formats.
You can find these files bundled with CUPS, and also extract them from your printer.
This file specifies what gets shown on the "page setup" dialog.
PPD files probably begin *PPD-Adobe:.
