Hi, I read the long discussion between Jeremias and Chris, and Jörg's note.
I do not like the idea of extension elements. I think, here I refer back to a recent post by Glen about standard FO files. I like the idea of a configuration file. Even a different configuration file for each single document is not a bad thing, possibly in addition to a more permanent configuration file with more permanent data like fonts. Surely most users do not like to write a configuration file often, but maybe someone can write a GUI for them to fire off FOP with the desired configuration. I also have a feeling of reinvention, not of TeX/DVI, but of the wheel. I do not know really much about printing. But I imagine this procedure. When I ask an application like Acrobat to print a file, it pops up a dialog. The dialog reads a printer capabilities file, as a PPD file or from the printer driver or from some other source. So the user makes a choice and the application inserts the appropriate commands for the user's choice into the output file. FOP is such a application, so that is what it should do. Do all these applications do the work themselves? I do not think so. They use a framework. Isn't Java's framework the Java Printing System? So FOP should use that. So definitely a configuration external to the FO file. And something like the Java Printing System to know the installed printer configuration and provide the user with the appropriate GUI and choice. Regarding a configuration file per printing run, recently a similar possibility was put forward for the user preferences for printer-specific image handling and other options. In a recent fop-user post I suggested the idea of hyphenation exceptions in a configuration file. Just my two cents. Simon -- Simon Pepping home page: http://www.leverkruid.eu