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).

The Envelope Specification scope is to provide a common system for identifying the protocol used to encode data, encrypting and decrypting that data, and identifying MetaNet hierarchy and ownership of the data in an unspendable output script.

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.