[vog]

> As a side-effect of its design, CT also enables the additional exchange of private "memo" data (such as invoice numbers or refund addresses)

This is a very interesting detail.

So it's finally possible to use bitcoin as a public ledger, by adding the hash value of any large dataset to the "memo". Up to now, we needed workarounds involving non-existing account, such as provided by Bitcoinproof: https://vog.github.io/bitcoinproof/