addresses being added to the final /8 pool and us finding ourselves with a pool of addresses that is increasing if we adopt this proposal. I believe that while this is a possibility it's not that likely an event. I'm not convinced that we will see large blocks of address space returned to IANA and the RIRs - I suspect that we're much more likely to see addresses exchanged on the open market. If we do see the address pool held by APNIC growing because of returned addresses then I think we should address the issue at that time and this policy should be adopted now. Good policy should encourage good behaviour and making it very clear to people that when we get into the final /8 that there will be one /22 each encourages people to get on with adding IPv6 to their networks instead of hoping the some hypothetical return of addresses will save them.