Colin Rafferty writes: I'm not arguing that the optimization is correct all the time. It's only works if you play by a certain set of rules, understanding the limitations. Without saved state, it is impossible to tell whether you're inside or outside a comment without starting from the beginning of the buffer, sweeping through the buffer and watching what comment and string delimiters go by. This is hellishly expensive. So, to speed parsing, it was decided that if you see something that would be a defun were it outside a comment or string, you assume that it _is_ outside a comment or string. The assumption is correct most of the time, and that's good enough unless you're using font-lock on a medical display. "Ooops, all those green life-sign indicators should be red! He's dead, Jim."