David -- I agree that breakage is not a good thing. It is reasonable to issue requirements for "new users", i.e., in this case things flowing in through various new directions. For the xml direction direct to LaTeX outside of xmltex, non-TeX pre-processing of CDATA to prepare for whatever you end up offering IMHO would be fine so long as it can be viewed as a one pass universal filter for chunks of CDATA. My guess is that you want to stick with the current internal character representation. -- Bill