Global printing options for all clients?

[Matthew Ford]

> Matthew Ford wrote:
> > I have a color inkjet printer, with an option "-o CNGrayscale" provided in the driver for grayscale printing. Since not all client software provides a grayscale printing option, I would like to set up two queues: one for color printing and one for grayscale. At first I tried setting this up using lpoptions - but it appears that the /etc/cups/lpoptions file only affects local print jobs submitted via "lpr", and not jobs submitted by remote clients. How can I set the grayscale option as a default for ALL jobs in this queue? Something in the printers.conf file, perhaps? I did not find anything in the web interface.
>
> If you are using CUPS 1.2 or higher, use:
>
>      lpadmin -p printer -o CNGrayscale-default=foo
>
> or if the option comes from a PPD file you can set the printer options
> from the web interface or use:
>
>      lpdmin -p printer -o CNGrayscale=foo

Thank you, the first lpadmin command worked. The grayscale option seems to be associated with a commented line at the end of the PPD file, as follows:

  *%CNPpdToOptKey CNGrayscale    --grayscale

What does this mean? Clearly CNPpdToOptKey is unique to the Canon driver, but I have no idea what purpose this line serves, and why the option should not appear in the web interface.