[ppml] IPv4 transfers

If IPv4 transfers are allowed but in a way that involves ARIN, then  
IPv4 addresses that are currently used in the ARIN region can only be  
obtained by organizations that are also in the ARIN region. ARIN has a  
little more address space under it than APNIC and the RIPE NCC: 29 /8s  
for ARIN, 26 for APNIC and the RIPE NCC, LACNIC has 6 and Afrinic 2.

However, if we include the legacy /8 space the picture becomes very  
different: of the 44 /8s that are allocated/assigned (from the  
delegation records on the RIR FTP servers) APNIC and RIPE both have  
one in their database, ARIN the other 42.

For the space that's under "various registries" (mostly legacy class  
B), ARIN governs 28.91 /8s, RIPE 6.91 and the other RIRs put together  
4.21 /8s.

Adding it all up:

ARIN:     29 + 42 + 28.91 = 99.91 /8s, 1676 million addresses
RIPE NCC: 26 +  1 +  6.91 = 33.91 /8s,  569 million addresses
ARPNIC:   26 +  1 +  3.28 = 30.28 /8s,  508 million addresses
LACNIC:    6 +       0.57 =  6.57 /8s,  110 million addresses
AfriNIC:   2 +       0.36 =  2.36 /8s,   40 million addresses

(After I disabled IPv6 I was able to visit the ARIN website and) I had  
a look at policy proposal 2007-27. This seems like a good way to solve  
this issue: ARIN would increase IPv4 maintenance fees, and with that  
finance a "buy back" program from legacy holders. The address space  
would then be shared with the other RIRs in accordance with 2007-27.