Eliezer S. Yudkowsky [firstname.lastname@example.org] wrote:
>My guess: PPLs require too much attention, for too small a group to
>make it necessary, and too small a reward to make it worth it.
I'm not so sure. All you really need is a database on the server where list members register their choice of PPL, such that it's added as a header in the outgoing mail. Recipients can then filter out the PPLs they don't want to receive mail from, and if senders break the restrictions imposed by their PPL the PPL owner can kick them out into 'anarchy'.
As long as we can filter on arbitrary headers, this would work.