I wouldn't have said they were exactly common, but I'd certainly be in
favor of them becoming mainstream rather than proposed.
The Oct 14 draft (am I out of date here?) gives no sample values for
REL and REV in the explanatory text, and describes them in the DTD as
%linktype; (="NAME") with a list to be supplied later. Do we have
proposals on these?
BTW, "URI" is referred to in the Oct 14 doc but not explained (I
think). What is the IETF status of the URI?
///Peter