Until today, I thought all addresses must start with
Well, behold 3M8XGFBKwkf7miBzpkU3x2DoWwAVrD1mhk, which is a multi-sig escrow address created to hold the bounty for the development of CoinJoin. This is both the first address I observed that doesn't start with
1, and the first multi-sig address that I've seen in the wild.
Are there other possible prefixes? What characterizes the different prefixes? (E.g. are all addresses that start with a
3 multisig addresses? Are there multisig addresses that do not start with a