The name of a local printer to which data is sent for printing.
(Note that PostScript files are sent to `ps-printer-name', which see.)
On Unix-like systems, a string value should be a name understood by
lpr's -P option; otherwise the value should be nil.
On MS-DOS and MS-Windows systems, a string value is taken as the name of
a printer device or port, provided `lpr-command' is set to "".
Typical non-default settings would be "LPT1" to "LPT3" for parallel
printers, or "COM1" to "COM4" or "AUX" for serial printers, or
"//hostname/printer" for a shared network printer. You can also set
it to the name of a file, in which case the output gets appended to that
file. If you want to discard the printed output, set this to "NUL".