BIP32 specifies a 4-byte version:
mainnet: 0x0488B21E public, 0x0488ADE4 private; testnet: 0x043587CF public, 0x04358394 private
BIP49 has a variant:
Extended public keys use 0x049d7cb2 to produce a "ypub" prefix, and private keys use 0x049d7878 to produce a "yprv" prefix. Testnet uses 0x044a5262 "upub" and 0x044a4e28 "uprv."
BIP84 has a variant:
Extended public keys use 0x04b24746 to produce a "zpub" prefix, and private keys use 0x04b2430c to produce a "zprv" prefix. Testnet uses 0x045f1cf6 "vpub" and 0x045f18bc "vprv."
What I notice about all these is the initial 0x04. And then I noticed in the Bitcoin Core test framework that this initial byte is spliced off and referred to as a “version”.
Is this the same “version” that BIP32 specifies? (Even though there is a 1 vs 4 byte discrepancy?) What other versions are there besides 0x04?
