user11429: I was wondering if I can add dummy data into a coinbase transaction’s inputs.
Is it possible to do this? Can you insert invalid input scripts into a coinbase transaction? Can you add multiple inputs scripts into a coinbase, do they all have to be legit scripts, if they do open inputs does the coinbase transaction send more than the regular block reward?

user208: Coinbase transactions must:

Have exactly 1 input.
That input must have prevout hash 0000...0000, and index 0xFFFFFFFF (an output which isn't actually spent).
The input's scriptSig must be between 2 and 100 bytes long.
Post BIP34 (2012), the scriptSig must start with a push of the block height in little endian encoding.
Be the first transaction in a block.

If it doesn't satisfy all these rules, the transaction, and the block it is in, are invalid.

11429: <p>I was wondering if I can add dummy data into a coinbase transaction’s inputs.
Is it possible to do this? Can you insert invalid input scripts into a coinbase transaction? Can you add multiple inputs scripts into a coinbase, do they all have to be legit scripts, if they do open inputs does the coinbase transaction send more than the regular block reward?</p>
 208: <p>Coinbase transactions must:</p>
<ul>
<li>Have exactly 1 input.</li>
<li>That input must have prevout hash 0000...0000, and index 0xFFFFFFFF (an output which isn't actually spent).</li>
<li>The input's scriptSig must be between 2 and 100 bytes long.</li>
<li>Post BIP34 (2012), the scriptSig must start with a push of the block height in little endian encoding.</li>
<li>Be the first transaction in a block.</li>
</ul>
<p>If it doesn't satisfy all these rules, the transaction, and the block it is in, are invalid.</p>
