There's no reason for any of the ideas in this thread to be in the same draft as the concepts outlined in autodiscovery-01. Stamp Out Creativity Now.
I'm strongly opposed to letting this draft turn into a vast metropolis of bikesheds, where we have 60-message threads on the right way to use HTML @rel values. The WG has limited resources and time. Those resources are most needed by the protocol draft. Bolting fancy new appendages on the autodiscovery draft is a waste of time. You don't need a standards action to add a link relation. Just do it. Robert Sayre