anchor.diff:  dns6,                           multiaddr,      0x37,           permanent,
   dnsaddr,                        multiaddr,      0x38,           permanent,
   protobuf,                       serialization,  0x50,           draft,     Protocol Buffers
  -cbor,                           serialization,  0x51,           draft,     CBOR
  +cbor,                           serialization,  0x51,           permanent, CBOR
   raw,                            ipld,           0x55,           permanent, raw binary
   dbl-sha2-256,                   multihash,      0x56,           draft,
   rlp,                            serialization,  0x60,           draft,     recursive length prefix
  
positive.code: skein1024-1008,                 multihash,      0xb3de,         draft,
  skein1024-1016,                 multihash,      0xb3df,         draft,
  skein1024-1024,                 multihash,      0xb3e0,         draft,
  poseidon-bls12_381-a2-fc1,      multihash,      0xb401,         draft,     Poseidon using BLS12-381 and arity of 2 with Filecoin parameters
  poseidon-bls12_381-a2-fc1-sc,   multihash,      0xb402,         draft,     Poseidon using BLS12-381 and arity of 2 with Filecoin parameters - high-security variant
  zeroxcert-imprint-256,          zeroxcert,      0xce11,         draft,     0xcert Asset Imprint (root hash)
  fil-commitment-unsealed,        filecoin,       0xf101,         permanent, Filecoin piece or sector data commitment merkle node/root (CommP & CommD)
  
negative.code: wss,                            multiaddr,      0x01de,         permanent,
  p2p-websocket-star,             multiaddr,      0x01df,         permanent,
  http,                           multiaddr,      0x01e0,         draft,
  json,                           serialization,  0x0200,         permanent, JSON (UTF-8-encoded)
  messagepack,                    serialization,  0x0201,         draft,     MessagePack
  libp2p-peer-record,             libp2p,         0x0301,         permanent, libp2p peer record type
  sha2-256-trunc254-padded,       multihash,      0x1012,         permanent, SHA2-256 with the two most significant bits from the last byte zeroed (as via a mask with 0b00111111) - used for proving trees as in Filecoin
  ripemd-128,                     multihash,      0x1052,         draft,
  ripemd-160,                     multihash,      0x1053,         draft,
  ripemd-256,                     multihash,      0x1054,         draft,
  