<p>"Relayed" and "mined" are completely separate processes and should not be conflated.</p>

<p>The transaction is valid, so it was perfectly fine to mine it (i.e. include it in a valid block).  </p>

<p>"Standard" is a more restrictive requirement, and as you say, this transaction is not standard.  That means that a default version of Bitcoin Core will not relay it, i.e. will not transmit it to other nodes on the Bitcoin peer-to-peer network.  But if the transaction reaches a miner some other way, they are perfectly free to include it in a block.</p>

<p>We can only speculate as to how that occurred in this case, but here are some possibilities:</p>

<ul>
<li><p>Some people were running a modified version of the Bitcoin client (or alternative Bitcoin software) that does relay non-standard transactions.</p></li>
<li><p>The creator of the transaction sent it directly to a miner, by some means other than the peer-to-peer network.  Some miners or pools have web sites where anyone can submit a transaction.</p></li>
<li><p>The transaction was created by the miner herself.</p></li>
</ul>

CC BY-SA 3.0
2016-08-14T19:56:59.983Z
Thanks for the fast answer! I had in fact assumed that "valid" and "fit to relay" were the same thing. And good to know about various ways to get a non-standard transaction mined.
synthetic
CC BY-SA 3.0
2016-08-14T16:21:52.210Z
2016-08-14T16:21:52.210Z
Nate Eldredge
<p>The OP_HASH256 puzzle transaction described <a href="https://en.bitcoin.it/wiki/Script#Transaction_puzzle" rel="nofollow">here</a> was mined in block 211997. But I read that only standard transactions (with outputs one of P2PK, P2PKH, bare multisig, P2SH, OP_RETURN) get relayed. So how did this transaction get relayed and mined?</p>

<transactions><non-standard-transaction>
How was transaction a4bfa8ab6435ae5f25dae9d89e4eb67dfa94283ca751f393c1ddc5a837bbc31b mined?
synthetic
# How was transaction a4bfa8ab6435ae5f25dae9d89e4eb67dfa94283ca751f393c1ddc5a837bbc31b mined?

(Asked by: username_0 on 2016-08-14)

The OP\_HASH256 puzzle transaction described [here](https://en.bitcoin.it/wiki/Script#Transaction_puzzle) was mined in block 211997. But I read that only standard transactions (with outputs one of P2PK, P2PKH, bare multisig, P2SH, OP\_RETURN) get relayed. So how did this transaction get relayed and mined?

**Tags:** transactions, non-standard-transaction


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## 1 answers

### Answer by username_1 on 2016-08-14. Score: 2 | Accepted answer

"Relayed" and "mined" are completely separate processes and should not be conflated.

The transaction is valid, so it was perfectly fine to mine it (i.e. include it in a valid block).

"Standard" is a more restrictive requirement, and as you say, this transaction is not standard. That means that a default version of Bitcoin Core will not relay it, i.e. will not transmit it to other nodes on the Bitcoin peer-to-peer network. But if the transaction reaches a miner some other way, they are perfectly free to include it in a block.

We can only speculate as to how that occurred in this case, but here are some possibilities:

* Some people were running a modified version of the Bitcoin client (or alternative Bitcoin software) that does relay non-standard transactions.
* The creator of the transaction sent it directly to a miner, by some means other than the peer-to-peer network. Some miners or pools have web sites where anyone can submit a transaction.
* The transaction was created by the miner herself.

> **Comments:**
> **username_0**: Thanks for the fast answer! I had in fact assumed that "valid" and "fit to relay" were the same thing. And good to know about various ways to get a non-standard transaction mined.  

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