Filtering Unregistered Blocks (WAS: small vent)

Well, there is the problem of where to look. There is a pretty
  comprehensive list of the delegation status of blocks at the
  /8 level that is pretty accurate. I suspect that the RIRs can
  provide pretty good detail for the recent (1996 and later) delegations.

  The historical delegations are -much- harder to track. I've been
  spending some time on clearing up detail on older /8 blocks
  and this data may make it into the publicly visable registries
  if they want it. is done and I've got most of complete.

-- bill