What Is the Practical Difference between “Opt-in RBF” and “Full RBF”?
The practical difference lies in the replacement policy of network nodes. Opt-in RBF (BIP125) requires the original transaction to explicitly signal its replaceability by setting the 'nSequence' field.
If the flag is absent, nodes generally won't relay a replacement. Full RBF is a node policy where any unconfirmed transaction, regardless of its RBF flag, can be replaced by a new, higher-fee transaction.
Full RBF maximizes the fee market but completely invalidates 0-conf security.
Glossar
Full Rbf
Derivation ⎊ Full Rbf, within cryptocurrency options and financial derivatives, signifies a complete representation of the risk-neutral density function, crucial for pricing and hedging exotic options.
Node Policy
Rule ⎊ Node Policy refers to the customizable set of internal rules and parameters that dictate how a full node interacts with the peer-to-peer network, specifically governing its acceptance, storage, and relay of unconfirmed transactions.
RBF
Policy ⎊ RBF (Replace-by-Fee) is a protocol feature that allows a user to replace an unconfirmed transaction in the mempool with a new transaction that includes a higher transaction fee.
Fee Market
System ⎊ The fee market describes the decentralized economic system where users compete for the limited resource of block space by offering transaction fees to network validators or miners.