BIP-110 (Reduced Data Temporary Softfork)
The 2025 proposal for a one-year soft fork limiting data fields, with a 55% threshold and mandatory signalling, whose 2026 enforcement split Knots nodes from Bitcoin.
Vlad predicted on S17 E17 that a Knots fork would let the market price BIP-110's ideas; on S17 E42 Bob Summerwill described the result grinding to a halt.[4][3]
Proposal
BIP-110, “Reduced Data Temporary Softfork”, lists Dathon Ohm as author and was assigned on 2025-12-03; its status in the BIPs repository is Closed[1]. Its abstract proposes to “Temporarily limit the size of data fields at the consensus level”[1]. The rules include invalidating new output scripts over 34 bytes (83 for OP_RETURN), pushes and witness items over 256 bytes, the Taproot annex, and Tapscripts with OP_SUCCESS or executed OP_IF[1].
Deployment
UTXOs created before activation are exempt, and the rules expire after an active_duration of 52416 blocks, “~1 year after activation”[1]. The deployment uses a modified BIP9 with a threshold of 1109/2016 (55%), a max_activation_height of 965664 and mandatory signalling of bit 4 in blocks 961632 to 963647, during which non-signalling blocks are rejected[1].
The split
Knots nodes enforcing BIP-110 began rejecting non-signalling blocks at height 961,632 on 8 August 2026, which split them from Bitcoin[2]. The minority SHA-256d chain then produced eight blocks in 22 days and became Bitcoin BLAKE2b[2]. Bob Summerwill described that chain grinding to a halt on S17 E42[3].
References
- primaryBIP-110 specification [archived]
- btkBitcoin BLAKE2b: The Fork That Fired the Miners (BTCTKVR: Forks!) [archived]
- episodeS17 E42: Bob Summerwill — the BIP-110 chain ground to a halt▶ listen at 38:26timestamp transcript-derived, pending a listen [archived]
- episodeS17 E17: Lukas Hozda on BIP-110 — Vlad on a possible Knots/BIP-110 fork▶ listen at 1:18:41timestamp transcript-derived, pending a listen [archived]