I used to use it as a CUPS feature, but as I said: I don't have cups-pdf installed, and indeed, I don't have CUPS installed at all. Perhaps it is being provide

I used to use it as a CUPS feature, but as I said: I don't have cups-pdf installed, and indeed, I don't have CUPS installed at all. Perhaps it is being provided by some system library (perhaps libcups), but not by CUPS itself.