Mark Bernstein points out the conflicting advice given by usability experts with regard to line-lengths. That's only the beginning when it comes trying to take seriously the recommendations on web accessibility and usability. There are backwards-compatibility issues (if I use CSS like I am supposed to, what happens to Netscape 4.x readers?); there's the still-inconsistent standards-compliance of "modern" browsers; there's the increasingly complex and confusing nature of the standards themselves. But beyond all of that, I have a nagging fear that what we are being asked to do is, in fact, impossible. A fundamental tenet of accessibility and standards-based design is the separation of document content, structure, and presentation (this goes back to the web's origins in the Text Encoding Initiative and SGML). I understand the rationale for this and, up to a point, I support it, but the entire field of graphic art and design, as well as a significant branch of textual studies will tell you that form and content are inseparable, that the presentation of a text is its meaning and not something that should be left over to the vagaries of a user agent. The "illuminated" works of William Blake are probably the most complete marriage of text, design and image in the English language, but you need look no further than the daily newspaper or a children's book to find examples where the line between medium and message is close to nonexistent (I challenge markup wonks to come up with a purely structural description of The Very Hungry Caterpillar). Web designers (unlike many other creators of electronic texts) are asked to create an ideal (in the Platonic sense) text, one that is independent of any particular presentation medium or physical embodiment (or that anticipates all possible instantiations). I'm not convinced that this entity is not a chimera.