BUIP???: Multiple OP_RETURN with shared size limit.

Jonathan Silverblood

Active Member
Nov 21, 2018
BUIP???: Multiple OP_RETURN with shared size limit.
Submitted by: Jonathan Silverblood
Date: 2019/11/14

The purpose of this BUIP is to get a commitment from Bitcoin Unlimited to support a change to the standardness rules that would allow for users to make and broadcast transactions with multiple OP_RETURN outputs given certain constraints.

I propose that we replace the standardness rule that enforces a maximum of one OP_RETURN output per transaction with a rule that instead enforces a total OP_RETURN size across all OP_RETURN outputs in a transaction. The existing rule for maximum size per individual OP_RETURN remains unchanged. The new limit on total size should be set so that it does not cause unnecessary issues and should be reasonable small.

A total size of 512b or 1024b are provided as an example for discussion and to set a ballpark of what the expectations are, but should not be seen as a requirement for this proposal.

By commiting to support this change to standardness, Bitcoin Unlimited would send a signal to other node software developers that this is something that is possible to change under consensus and would help start the necessary discussions in the community.

With the expanse of OP_RETURN based protocols and the widespread adoption of SLP tokens there is a need to enable cross-protocol collaboration. We cannot predict all possible usecases for this feature, but there is already several protocols that either see a benefit to this (CashIntents with SLP) or that are working around this limitation in awkward ways (SLP and SLPDEX).

Multiple OP_RETURN with shared size limit.