Thank you Radu. Meanwhile, I have also found this alternative: 1. Generate output, using the "default" commonltr.css file in the OXYGEN_INSTALL_DIR\frameworks\dita\DITA-OT\resource\ folder. 2. Customize the commonltr.css file in the output folder. 3. Rename the "default" commonltr.css file in the OXYGEN_INSTALL_DIR\frameworks\dita\DITA-OT\resource\ folder to, for example, "commonltr.css.original". When I regenerate the output, the OT cannot find commonltr.css in the OXYGEN_INSTALL_DIR\frameworks\dita\DITA-OT\resource\ folder, so it won't be copied to the output folder, and I will still have the original commonltr.css file, just in case. But I guess your first alternative is the cleanest. I'll try that one. Cheers -- Yves Barbion www.scripto.nu