At the most receint NANOG some methods of delegating DNS (in-addr.arpa's) on
non octet boundaries was disccused. If I remember correclty
there were two parts to this, regarding delegating individual
records, and some other process.
If anyone has any references to this, I would apprecated it.
We are looking into this and also automatic or assisted
renumbering to help reduce allocation growth and router
table sizes.