The debate over Bitcoin’s OP_RETURN opcode and its 80-byte limit has escalated into what some are calling the “OP_RETURN War of 2025.” On May 15, block 896,696 set a record by including an unusually large non-standard OP_RETURN transaction that occupied nearly the entire block with a single transfer, approaching 1 MB of arbitrary data.
OP_RETURN Rickrolling and Creative Expression
OP_RETURN allows embedding up to 80 bytes of unspendable data without bloating the UTXO set. Recently, a proposal to remove this limit has gained traction among developers and the broader community. Some users have turned OP_RETURN into a canvas for memes—one message cleverly adapts Rick Astley’s 1987 hit: “Never gonna give you OP_RETURN. never gonna let you down…” Another reads: “Filters have a huge influence on what gets mined.”
The ‘First-Ever 1 Megger’ Block
A group known as The Wizards of Ord created block 896,696 showcasing their full set of 3,333 inscriptions. “We just created the largest OP_RETURN in Bitcoin history,” tweeted @lifofifo. “Introducing the first-ever 1 megger, Block 896696, which includes every single The Wizards of Ord in OP_RETURN data.” To bypass the 80-byte policy—which is not a consensus rule but a default relay policy—the creator submitted the non-standard transaction directly to Marathon Digital (MARA) mining pool, which chose to include it. The transaction used SegWit-enabled Bitcoin format v2, sent 0 BTC, and relied on a generous fee to incentivize the miner.
Bitcoin Knots Node Adoption Surges
Amid the on-chain message frenzy, the Bitcoin Knots node implementation has seen a noticeable uptick in adoption. Unlike Bitcoin Core, Knots retains -datacarrier and -datacarriersize flags, giving operators granular control. Setting -datacarrier=0 rejects all OP_RETURN transactions; adjusting -datacarriersize enforces stricter caps like 80 bytes. These parameters filter incoming transactions from the mempool, halting their propagation. Knots now runs on about 2,000 nodes, up from 600 in mid-March, though still far behind Bitcoin Core’s 19,470 visible nodes.
As Bitcoin’s role evolves, the recent OP_RETURN experiments signal growing demand for creative control at the protocol’s edges. With node software diverging and miners responding to new incentives, the network is entering a phase of quiet redefinition—where policy, purpose, and participation are tested one byte, one block, and one meme at a time.