Direct Payment Protocol is a protocol for communication between a payment host (usually either a merchant, a payment processor, or simply the recipient’s wallet) and their customer (the sender of the funds).

Paymail standardises a communication protocol that offers global user-memorable handles backed by service discovery, feature negotiation, and an extension mechanism for communication between Bitcoin wallets and applications.

The primary purpose of this Travel Rule specification is to define a standardised protocol for VASPs on the BitcoinSV blockchain to collect and exchange the information required by the Travel Rule.