Remove BIP 110 following unsuccessful activation attempt #2247

Summary

Remove BIP 110, its test vectors, and its entry from the BIP index following the unsuccessful attempt to activate it on Bitcoin.

Rationale

BIP 110 required mandatory version-bit signaling beginning at block height 961632. Blocks 961632 through 963647 that did not signal bit 4 were invalid under the proposal.

At height 961632, Bitcoin's accumulated-work chain accepted block:

• Hash: 00000000000000000000d1e01392faa65ceeaed307f0a3159144b84146ff24ba
• Header timestamp: 2026-08-08 19:35:55 UTC
• Version: 0x20006000
• BIP 110 bit 4: not set

BIP-110-enforcing nodes rejected that block and followed an alternative signaling block mined by OCEAN:

• Hash: 0000000000000000000169eb6f811ddbd0daf343af7b62180cdb13e7c78dbc16
• Header timestamp: 2026-08-08 20:12:12 UTC
• Version: 0x27d60010
• BIP 110 bit 4: set

Scope

This removes:

• bip-0110.mediawiki
• bip-0110/test-vectors.json
• bip-0110/test-vectors.py
• The BIP 110 entry from README.mediawiki

References

• BIP 110 deployment rules: https://github.com/bitcoin/bips/blob/master/bip-0110.mediawiki#deployment
• Bitcoin-chain block 961632: https://mempool.space/block/00000000000000000000d1e01392faa65ceeaed307f0a3159144b84146ff24ba
• BIP-110 signaling block 961632: https://mempool.guide/block/0000000000000000000169eb6f811ddbd0daf343af7b62180cdb13e7c78dbc16
• fork.observer report: https://fork.observer/rss/1/forks.xml

NACK

I think it's important for failed BIPs to be preserved for educational purposes.

Those who do not learn from history are doomed to repeat it.

@callebtc please see the PR description of #2245 and the process described in BIP 3.

BIPs do not get deleted, they are retained even after being updated to Closed.

@callebtc,

So basically what you want is a BIP-1102 that does the opposite of BIP-110? 😄 Keep the current OP_RETURN rules and let the fee market decide?

I have several other questions about BIP-110 that haven't been answered yet. See my comment here: #2245 (comment)

@callebtc,

So basically what you want is a BIP-1102 that does the opposite of BIP-110? 😄 Keep the current OP_RETURN rules and let the fee market decide?

I have several other questions about BIP-110 that haven't been answered yet. See my comment here: #2245 (comment)

If reversing BIP-110 is considered out of scope for this PR, and proposing a competing BIP (BIP-1102) is also considered off-topic, where is the appropriate place to propose and discuss the alternative?