TERM_DEF // UPGRADES_BIPS / BIP_61_REJECT_MESSAGE
BIP 61
(REJECT MESSAGE)
(REJECT MESSAGE)
BIP 61 (Reject Message). P2P reject message; deprecated due to leaking node policy.
This page sits in the Upgrades & BIPs section — The proposal process and the major upgrades that shaped Bitcoin. Read on for what it is, why it exists, how it works under the hood, and what to watch out for.
This page sits in the Upgrades & BIPs section — The proposal process and the major upgrades that shaped Bitcoin. Read on for what it is, why it exists, how it works under the hood, and what to watch out for.
WHAT_BIP_61_REJECT_MESSAGE_IS
BIP 61 (Reject Message) — at a glance
UPGRADES
BIP 61 — "Reject Message" is a proposal in the Networking family, first published in 2015 with status rejected. P2P reject message; deprecated due to leaking node policy. Its technical mechanism: reject message with code + reason — deprecated for fingerprinting + spam concerns. removed from Bitcoin Core 0.20 (2020)
Why it exists
DESIGN
BIP 61 (Reject Message) exists to solve a specific problem: tell a peer why their tx/block was rejected. Without a written, numbered spec, every wallet and node implementer would interpret the requirement differently — and Bitcoin's value depends on every implementation agreeing exactly. BIP-61 is the single source of truth for this concern, so any new client built today can match the behaviour of every client built since 2015.
HOW_IT_WORKS
Mechanism
HOW IT WORKS
Mechanically, BIP-61 reject message with code + reason — deprecated for fingerprinting + spam concerns. Adoption today: removed from Bitcoin Core 0.20 (2020).
1. Author drafts BIP-61 against the BIP-2 template — abstract, motivation, specification, rationale.
2. The text + a reference implementation are posted on the bitcoin-dev list and as a PR to bitcoin/bips.
3. Reviewers tear it apart: ambiguities, security concerns, edge cases, interaction with prior BIPs.
4. Once stable, the BIP editor merges it; it gets a number (BIP-61) and the status "draft" or "proposed".
5. Implementations land in Bitcoin Core / wallets / other clients. For consensus changes: activation parameters chosen.
6. After deployment + adoption, BIP-61 is promoted to "final"; deprecated proposals get "replaced" or "withdrawn".
WORKED_EXAMPLE
BIP-61 — quick reference card
EXAMPLE
BIP number : 61
Title : Reject Message
Area : Networking
First published: 2015
Status : rejected
Fork class : no
Motivation : tell a peer why their tx/block was rejected.
Mechanism : reject message with code + reason — deprecated for fingerprinting + spam concerns.
Where it shows up : removed from Bitcoin Core 0.20 (2020).
Read the spec : https://github.com/bitcoin/bips/blob/master/bip-0061.mediawiki
KEY_PROPERTIES
OPT-IN
No authority can force a BIP on anyone. Adoption depends entirely on whether the change is genuinely useful.
NUMBERED
Stable numeric reference — BIP-61 means the same thing across every wallet, miner, and node that has read this spec.
NON-CONSENSUS
BIP-61 is not a consensus rule — clients can implement it without coordinating with the network at large.
SUPERSEDED
BIP-61 is no longer active — either replaced by a later BIP or rejected after review.
COMMON_PITFALLS
Things that catch people out
PITFALLS
- BIP-61 is no longer active. If you read it in a tutorial, double-check whether the actual current spec is a later BIP.
- Don't confuse "draft" / "proposed" / "final" status — read the BIP header before relying on it in production.
- The BIP number is just an editorial counter — it doesn't imply correctness or stability. Always cross-reference with the latest bitcoin/bips repo.
RELATED_CONCEPTS
Other terms from Upgrades & BIPs — click any to read its page:
TERMINOLOGY_INDEX
TERMINOLOGY
BIP 61 (Reject Message)
P2P reject message; deprecated due to leaking node policy.
Segregated Witness (SegWit, BIP 141)
The 2017 upgrade separating witness-data/">witness data, fixing tx malleability, and introducing weight units.
Taproot (BIP 341)
Tapscript (BIP 342)
Script-language updates accompanying Taproot — new opcodes, removed limits.
Schnorr (BIP 340)
The Schnorr signature spec adopted by Taproot.
BIP Process
The community workflow for proposing, discussing, and tracking changes to Bitcoin.
Soft Fork Activation
MASF (Miner-Activated Soft Fork)
Activation triggered by miner signaling in block versions.