Pay to False Return
The blockchain can carry data as well as money, but data has to be attached to an output nobody can spend. This defines how to write such an output and the practices to follow when putting data in one.
8 standards
Data in script
Using an output to carry content rather than value: a run of bytes after an unspendable opcode, or a file wrapped in an inscription envelope. Standards here define the shapes that content takes.
Also searched as OP_RETURN, OP_FALSE, inscription, on-chain data, payload.
What OP_RETURN means
OP_RETURN is a Bitcoin script opcode that marks an output as unspendable while allowing arbitrary data to be attached after it. It is commonly used to embed metadata or application data directly on the blockchain.
Open in the glossaryFiled under
8 standards, spread across 3 of the 12 topics.
Start with
BRC-18
Pay to False Return
The blockchain can carry data as well as money, but data has to be attached to an output nobody can spend. This defines how to write such an output and the practices to follow when putting data in one.
Filed under Scripts
Standards about this
Data in script is the main subject of these 3.
18 19 Pay to True Return
Attaching data to an unspendable output means the coins attached to it are gone for good, which some argue is the wrong way to think about Bitcoin. This offers a way to carry data on an output that can still be spent afterwards.
145 Registry-Free Typed Content Anchor with On-Chain Code Provenance
Committing to a piece of content along with what kind of thing it is usually means registering the type somewhere. This derives a single fixed-length commitment from the type and content directly, so no registry is needed.
Standards that touch it
These are about something else, and deal with data in script on the way.
48 Pay to Push Drop
Attaching data to an output normally makes it unspendable, so the data and the ownership cannot travel together. This describes a script that carries arbitrary data and leaves the output spendable, letting a token hold its own details.
122 Auditable Real-time Inference Architecture (ARIA)
When an AI system makes a decision that matters, there is usually no way to check afterwards what it actually did. This records each decision so it can be independently verified later, without exposing the model itself.
160 1Sat Ordinals — Inscription Envelopes
A tiny on-chain token can prove it is unique and traceable, but on its own it carries no real content, it cannot hold a picture, a document, or app data. Developers needed a standard way to attach that content directly to the token so wallets and apps can find and display it without inventing their own format.
161 BSV-21 Fungible Tokens (JSON / Legacy)
Issuing a fungible token, like a points balance or stablecoin unit, on Bitcoin used to mean inventing your own tracking scheme or relying on a global name registry that anyone could squat or collide with. There was no agreed way to say "this balance belongs to this token, forever" without a central ledger, and no standard way for an issuer to mint more supply later without rewriting the rules each time. This standard fixes the token's identity to the transaction output that created it and lets ordinary wallet transactions carry and mint balances.
217 Authenticated 1Sat Inscription
If you inscribe content onto a Bitcoin satoshi, anyone can copy the exact bytes into a new output and claim they made it, because the inscription itself proves content existed but not who put it there. Meanwhile, naive ways of adding a signature or label to that output can accidentally make the coin permanently unspendable, freezing the token forever. This standard fixes the layout so you can prove authorship and still move the token.
Usually read alongside
Concepts that keep appearing on the same standards as this one.
Was this helpful?