user2311: I was under the impression that null-data transactions were standard, but whenever I try to broadcast one it takes a while for it to appear in a block.
I tested this by broadcasting 2 transactions with same fees and same priority. The standard one got picked up in the next block, while the null-data one has yet to appear in a block (there's been 3 non-full blocks mined so far).
example tx: https://live.blockcypher.com/btc/tx/c0b0de8662054cadd461b488676a374f8f962c91612070e8e23b95d108d36217/
Am I doing anything wrong to make this transaction non-standard?

user12983: 
Not all miners accept transactions with null-data (OP_RETURN)
outputs
Not all nodes relay such transactions
Are you sure that your null-data transaction is standard (for clients 0.9.x+) ?

UPD: your output is 6a74686973206973206120746573740d0a and decoded to:
OP_RETURN // 6a
OP_DEPTH  // 74
OP_ENDIF  // 68 ... oups!

This is non-standard output. Because null-data output should contain only one OP_PUSH operation, not an arbitrary bytes

2311: <p>I was under the impression that null-data transactions were standard, but whenever I try to broadcast one it takes a while for it to appear in a block.</p>

<p>I tested this by broadcasting 2 transactions with same fees and same priority. The standard one got picked up in the next block, while the null-data one has yet to appear in a block (there's been 3 non-full blocks mined so far).</p>

<p>example tx: <a href="https://live.blockcypher.com/btc/tx/c0b0de8662054cadd461b488676a374f8f962c91612070e8e23b95d108d36217/" rel="nofollow">https://live.blockcypher.com/btc/tx/c0b0de8662054cadd461b488676a374f8f962c91612070e8e23b95d108d36217/</a></p>

<p>Am I doing anything wrong to make this transaction non-standard?</p>
 12983: <ol>
<li>Not all miners accept transactions with null-data (OP_RETURN)
outputs</li>
<li>Not all nodes relay such transactions</li>
<li>Are you sure that your null-data transaction is standard (for clients 0.9.x+) ?</li>
</ol>

<p>UPD: your output is 6a74686973206973206120746573740d0a and decoded to:</p>

<pre><code>OP_RETURN // 6a
OP_DEPTH  // 74
OP_ENDIF  // 68 ... oups!
</code></pre>

<p>This is non-standard output. Because null-data output should contain only one OP_PUSH operation, not an arbitrary bytes</p>
