Overview
- A Bitcoin Core contributor publicly floated a plan in mid‑June to stop wallets emitting the old BIP125 replace‑by‑fee (RBF) opt‑in signal because the network now treats unconfirmed transactions as replaceable by default.
- Full‑RBF was made the default mempool policy in Bitcoin Core in October 2024, which left the opt‑in nSequence flag operationally redundant but still visible on‑chain.
- The nSequence field is mandatory for every input so wallets cannot simply omit the signal; developers are therefore pushing to standardize on a common value, most likely the already dominant MAX‑2.
- Data and developer comments show about three quarters of transactions already use MAX‑2, but uneven adoption could make the remaining wallets more fingerprintable unless the ecosystem coordinates.
- This is a wallet‑level cleanup that would not change consensus or fee‑bumping rules, yet it could improve user privacy and force merchants and services to stop treating visible RBF flags as a safety signal.