I think this is hasty, and should be left out of IPP/1.1. I wasn't
calling for changes to IPP/1.1, I just think that IPP/1.1 is good
for printing, which it's designed to do, and it's not perfect
for messaging or e-printing or ifaxing or ipp-ing, which it wasn't
designed to do.
I think that 'sender and recipient identification' aren't as easy
as adding attributes to the job.