odd-to-html doesn't handle content models containing both relaxng and odd very well

[lb42]

it's still possible (tho hard to justify) to have datatypes expressed using a combination of ODD elements and RNG components (for an example, see the attached, taken from the "oddmanual" document) : the Relaxng schema generated from this is fine, but the HTML spec has nothing in the "Content" and "Datatype" slots. Maybe it should just say "[mulatto] and move on.. odd6.txt