<p>The main use of op_return outputs is that junk gets written to op_return outputs instead of output scripts that are part of the UTXO set.</p>

CC BY-SA 4.0
2024-04-19T19:30:32.187Z
2024-04-19T19:30:32.187Z
Murch
<p>Some time a go I heard from <a href="https://www.bitcoinmechanic.ca/about" rel="nofollow noreferrer">Bitcoin Mechanic</a> that there was a coin join implementation that inscribes some data that they need in order to determine their pricing.
Is that true? Do custodians such as Liquid use OP_RETURN for anything?
Other than for <a href="https://petertodd.org/2016/opentimestamps-announcement" rel="nofollow noreferrer">many forms</a> of <a href="https://rodarmor.com/blog/runes/" rel="nofollow noreferrer">spam</a>, what is OP_RETURN used for in non-coinbase transactions?
Or in other words, lets say that starting from tomorrow there is no OP_RETURN other than that used in coinbase transactions, what would be broken in such scenario?</p>

CC BY-SA 4.0
2024-04-19T19:22:02.410Z
Related: https://bitcoin.stackexchange.com/q/105881/5406
Murch
<script><op-return><spam>
Other than for obvious spam, what is OP_RETURN used for in non-coinbase transactions?
John Smith
# Other than for obvious spam, what is OP_RETURN used for in non-coinbase transactions?

(Asked by: username_0 on 2024-04-19)

Some time a go I heard from [Bitcoin Mechanic](https://www.bitcoinmechanic.ca/about) that there was a coin join implementation that inscribes some data that they need in order to determine their pricing.
Is that true? Do custodians such as Liquid use OP\_RETURN for anything?
Other than for [many forms](https://petertodd.org/2016/opentimestamps-announcement) of [spam](https://rodarmor.com/blog/runes/), what is OP\_RETURN used for in non-coinbase transactions?
Or in other words, lets say that starting from tomorrow there is no OP\_RETURN other than that used in coinbase transactions, what would be broken in such scenario?

**Tags:** script, op-return, spam

> **Comments:**
> **username_1**: Related: https://bitcoin.stackexchange.com/q/105881/5406  

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## 1 answers

### Answer by username_1 on 2024-04-19. Score: 1 | Accepted answer

The main use of op\_return outputs is that junk gets written to op\_return outputs instead of output scripts that are part of the UTXO set.


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