I am broadly supportive of the principle behind this proposal. However the detail needs some refinement IMO. It's not clear what is meant by "Tier-0/1" or even "ENUM". This needs to be clarified. I think we all know what we mean by these terms. But the proposal does not define them or incorporate a definition by reference. My worry here is that if "ENUM" in particular is not defined, the proposal as written opens up a pandora's box. Does it apply *exclusively* to the public e164.arpa tree? If not, which other flavours of ENUM does the proposal cover? I'm thinking here of potential implementations of Infrastructure ENUM which could be done either on the public Internet or behind closed doors between telcos: should these be entitled to a /24 for anycasting too? Let's say two telcos implement some form of Infrastructure ENUM for cross-operator routing. Will this proposal mean they will both be entitled to a /24 for their respective ENUM trees? Since telcos tend to use bi-lateral agreements, there is the prospect here of forests of ENUM trees. Each telco could well have a tree for each telco it has a bi-liateral agreement for Infrastructure ENUM and each of these trees could be entitled to a /24 for anycasting.