ons that were re-added in the active chain will appear as-is in this array, and may thus have a positive confirmation count.
  ],
  "lastblock": "lastblockhash"     (string) The hash of the block (target_confirmations-1) from the best block on the main chain. This is typically used to feed back into listsinceblock the next time you call it. So you would generally use a target_confirmations of say 6, so you will be continually re-notified of transactions until they've reached 6 confirmations plus any new one