<p>From he official <a href="https://bitcoin.org/en/developer-guide#standard-transactions" rel="nofollow">Developer Guide</a>:</p>

<blockquote>
  <p>Null data scripts let you add a small amount of arbitrary data to the
  block chain in exchange for paying a transaction fee, but doing so is
  discouraged. (Null data is a standard script type only because some
  people were adding data to the block chain in more harmful ways.)</p>
  
  <blockquote>
    <p>script: OP_RETURN &lt;data> <br>(Null data scripts cannot be spent, so there's no scriptSig)</p>
  </blockquote>
</blockquote>

<p>Another <a href="http://bitcoinhistory.net/Technical_Papers/ProgrammingBitcoinTransactionScripts.pdf" rel="nofollow">information</a> (which is related to your example):</p>

<blockquote>
  <p>This pattern is often used to encode data in the blockchain. After the OP_RETURN you can
  insert arbitrary data. The advantage is that the simple bitcoin nodes can prune the transaction
  saving memory, while full nodes will hold it. This is considered good behavior when
  ‘misusing’ the blockchain for storing data.</p>
</blockquote>

<p>As you can see in your example there are data following the OP_RETURN so it was used to encode data into the blockchain.</p>

CC BY-SA 3.0
2014-07-28T10:58:01.650Z
It's not about simple vs. full nodes. OP_RETURN transaction outputs are not added to the UTXO database (the set of all spendable coins) of full nodes, but are added to the blockchain. So it's just slightly less harmful.
Pieter Wuille
CC BY-SA 3.0
2017-12-31T11:52:41.027Z
But still - what kind of data is stored here?
Frank Meulenaar
CC BY-SA 3.0
2018-03-27T18:53:39.103Z
The link to http://bitcoinhistory.net/Technical_Papers/ProgrammingBitcoinTransactionScripts.pdf is dead.
Joachim Breitner
CC BY-SA 3.0
2014-06-28T09:48:41.490Z
2014-06-28T09:53:47.397Z
2014-06-28T09:53:47.397Z
Dennis Kriechel
<p>Can someone give more information on that type of transaction? Why is it useful for the network. Can it be claimed since it has OP_RETURN command?</p>

CC BY-SA 3.0
2014-06-28T09:47:41.217Z
http://blockexplorer.com/rawtx/d29c9c0e8e4d2a9790922af73f0b8d51f0bd4bb19940d9cf910ead8fbe85bc9b

Here is an example
angel limneos
<transactions>
Nulldata transaction information
angel limneos
# Nulldata transaction information

(Asked by: username_0 on 2014-06-28)

Can someone give more information on that type of transaction? Why is it useful for the network. Can it be claimed since it has OP\_RETURN command?

**Tags:** transactions

> **Comments:**
> **username_0**: http://blockexplorer.com/rawtx/d29c9c0e8e4d2a9790922af73f0b8d51f0bd4bb19940d9cf910ead8fbe85bc9b  Here is an example  

---

## 1 answers

### Answer by username_1 on 2014-06-28. Score: 3

From he official [Developer Guide](https://bitcoin.org/en/developer-guide#standard-transactions):

> Null data scripts let you add a small amount of arbitrary data to the
> block chain in exchange for paying a transaction fee, but doing so is
> discouraged. (Null data is a standard script type only because some
> people were adding data to the block chain in more harmful ways.)
>
> > script: OP\_RETURN <data>   
> > (Null data scripts cannot be spent, so there's no scriptSig)

Another [information](http://bitcoinhistory.net/Technical_Papers/ProgrammingBitcoinTransactionScripts.pdf) (which is related to your example):

> This pattern is often used to encode data in the blockchain. After the OP\_RETURN you can
> insert arbitrary data. The advantage is that the simple bitcoin nodes can prune the transaction
> saving memory, while full nodes will hold it. This is considered good behavior when
> ‘misusing’ the blockchain for storing data.

As you can see in your example there are data following the OP\_RETURN so it was used to encode data into the blockchain.

> **Comments:**
> **username_2**: It's not about simple vs. full nodes. OP_RETURN transaction outputs are not added to the UTXO database (the set of all spendable coins) of full nodes, but are added to the blockchain. So it's just slightly less harmful.  
> **username_3**: But still - what kind of data is stored here?  
> **username_4**: The link to http://bitcoinhistory.net/Technical_Papers/ProgrammingBitcoinTransactionScripts.pdf is dead.  

---

