In 2014, Bitcoin Core launched OP_RETURN with an 80-byte default cap, enforced by means of the -datacarriersize possibility. This was meant to permit small information (reminiscent of proofs or certificates) whereas discouraging spam.
After Taproot was activated in 2021, individuals started embedding massive quantities of knowledge in witness fields. These inscriptions bypassed the OP_RETURN cap and weren’t affected by -datacarriersize.
In 2022, the definition of -datacarriersize was modified so it utilized solely to uncooked OP_RETURN outputs. In 2023, a pull request to broaden its scope to cowl witness information was closed with out merging resulting from controversy and lack of consensus.
In Bitcoin Core v30 (2025), the OP_RETURN cap has been eliminated, a number of OP_RETURN outputs are allowed, and -datacarriersize is deprecated.
My questions:
- Why was -datacarriersize narrowed to OP_RETURN solely in 2022 as a substitute of expanded to cowl witness-based information carrying?
- What had been the primary causes for not merging the 2023 pull request that proposed increasing it?
- How do the upcoming v30 modifications align with the unique anti-spam intent of -datacarriersize and OP_RETURN?
- What steerage would you give to node operators who need stricter limits on data-carrying transactions?
