[ietf-dkim] RFC4871bis - whether to drop -- k: Key type

[Siegel, Ellen]

> 
> >    TXT RR tags
> 
> >      k: Key type
> >
> > Much the same as h=, with the added issue that there's only one
> > possible key type right now, and if there were a need for k= in the
> > future it could be added in the same RFC that adds support for
> > anything other than RSA.
> 
Dropping this to remove clutter seems like a reasonable idea, but it would be necessary to meet a couple of conditions to prevent breakage due to the number of existing records with this tag. 

	- implementations would have to ignore any tags they don't recognize (this should already be required, so should be no problem)

	- if this functionality is added back in later, it needs to be done in a way that breaks neither records with k tags nor records without a key type specifier (again, backwards compatibility requirements should make this obvious, but if enough time elapses it's possible people will forget about the existing k tags).