It is certainly illuminating to be forced to determine which elements of a page are rendering and which are content. The problem with markup is more troubling, though. Well-tagged electronic text aims to result in an approximation of the page from which it stems. Good taggers preserve features such as line-breaks and remain aware of the need to tag for rendering and content separately, so that the rendering is as close as possible in appearance to the source page. Their successes are real, but they are grossly limited.
Representation is never reproduction .
The essence of the PAGE is appearance . A coherent practice of image-based editing is called for. What the reader sees should, as closely as possible without sacrificing the utility of an electronic edition, preserve the appearance of the source-page. The best possible outcome of this negotiation is an edition featuring a virtually transparent interface . One can imagine other editing projects which would require different basic units.