MEP for type-and-role data

Hi all,

I posted earlier a proposal for lookup rule for type-and-role data,
such as link titles, sort titles, descs, and thumbs. I've written a MEP
with this proposal:

http://projectmallard.org/mep/mep0018

I've also revised three older MEPs to use this new proposal:

The thumb Element:
  http://projectmallard.org/mep/mep0004

Multiple desc Elements:
  http://projectmallard.org/mep/mep0008

Roles on Sort Titles:
  http://projectmallard.org/mep/mep0011

Feedback appreciated.

Thanks,