Companion

This is used for identity and payments on any blockchain (there is value in having the same address across blockchains sometimes, but its also potentially dangerous if two blockchains use exactly the same tx format, sighash scheme, and a reproducible (non-UTXO) input form. This seems unlikely.

BIP-44 coin types are described (here)https://github.com/satoshilabs/slips/blob/master/slip-0044.md