With this, absolutely transparent printing of every document regardless of the software on the server would be possible. If the user wants to print a document in a language which needs a special font which is not a standard PostScript font or when he has some additional fonts installed on his desktop machine, they are not necessarily on the remote print server or in the hardware PostScript interpreter of the printer. So adding fonts to GhostScript does not help in most cases. Note that CUPS renders the PostScript on the server and not on the client, where the users have their individual fonts installed. This leads to simply printing in a latin default font, even if the font needed for the language is correctly installed and available for printing.
Some languages have more than one encoding.
So 3. cannot always be solved by autodetection. A preview is needed. This cannot be done by a CUPS filter, because the filters run on the server. All command line options which it does not use for itself, should be passed to the printing program it actually calls. This way we do not need to change the default print commands of all programs of Linux Mandrake.