Chris, I was specifically thinking about the e-TeX 1.1 primitives \ifundefined and \protected. Reimplementing \DeclareRobustCommand using \protected would be such a task. Of course, the new \mark features can be exploited by new document classes or packages to the existing classes. And we shouldn't forget, that e-TeX extends TeX--XeT and allows right-to- left typesetting. --J"org Knappen.