(Brion Vibber vibber@aludra.usc.edu):
Interlanguage links should produce <link> tags to go in the <head> ...
Well yes, that would be a nice way to encode them, but then they'd only be available to browsers that allowed access to page-level links. Few do, and even those don't make it easy. We already use typed links to point to the page's stylesheet and icon, which some browsers will use and the rest safely ignore; but most other types of links don't have any browser support at all.