24 nVersion bits for general purpose use

The five-minute read

One action, walked through

1. Open BIP 323 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: 24 bits are reserved in the nVersion field as extra nonce space for miners, providing for additional hashrate with header-only mining without relying on rolling nTime more often than once per second.
3. Name the object that changes: BIP8, BIP9.
4. Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.

The argument, unpacked

What has to be true

• You are implementing BIP 323 at the status the text itself states: Draft.
• The object that has to change is BIP8, BIP9. A neighbouring document with a similar name is not this one.
• Status in the header is not adoption.

What happened after the paper

The source marks this draft. It is not a live consensus rule just because it has a number. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

• What must an implementation of 24 nVersion bits for general purpose use accept, and what may it ignore?
• Is this consensus, peer policy, or an application interface?
• Which names does the text pin down: BIP8, BIP9?

Terms

BIP 323

The public text titled 24 nVersion bits for general purpose use.

Draft

The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

An interface that is only a name in a repository will be re-implemented differently by every team, which is how shared contracts break.

What the design proposes

• 24 bits are reserved in the nVersion field as extra nonce space for miners, providing for additional hashrate with header-only mining without relying on rolling nTime more often than once per second.
• BIP 320 defined 16 bits of nVersion as nonce space for additional nonce space.
• It turns out that this isn't enough, as some devices have started using 7 bits from nTime for extra nonce space (see https://github.com/stratum-mining/sv2-spec/discussions/187).

How the mechanism is specified

• Taken from the specification, the next constraint is: BIP 320 defined 16 bits of nVersion as nonce space for additional nonce space.
• Locate BIP8, BIP9 in BIP 323 and apply it to one transaction or call.
• Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.

What this page does not treat as proven

• This document does not set a fee, a valuation, or a security proof.
• Status in the header is not adoption.
• The source marks this draft. It is not a live consensus rule just because it has a number.

Why a venture studio still reads it

Use BIP 323 when a pitch says '24 nVersion bits for general purpose use' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.