user3750: If a block:

Is after the last halving, so there is no subsidy
Includes no non-coinbase transactions, so there are no fees

Must it include a coinbase transaction? If so, will it simply have no outputs?

user208: Every Bitcoin block is required to have a coinbase transaction, regardless of fees or subsidy.
Additionally, every transaction (including the coinbase), must have at least one output (possibly 0-valued), and at least one input (in the case of a coinbase, this isn't actually spending any actual UTXO, though).
In a block with 0 fees and 0 subsidy, this implies a coinbase transaction with only 0-value outputs.

3750: <p>If a block:</p>
<ul>
<li>Is after the last halving, so there is no subsidy</li>
<li>Includes no non-coinbase transactions, so there are no fees</li>
</ul>
<p>Must it include a coinbase transaction? If so, will it simply have no outputs?</p>
 208: <p>Every Bitcoin block is required to have a coinbase transaction, regardless of fees or subsidy.</p>
<p>Additionally, every transaction (including the coinbase), must have at least one output (possibly 0-valued), and at least one input (in the case of a coinbase, this isn't actually spending any actual UTXO, though).</p>
<p>In a block with 0 fees and 0 subsidy, this implies a coinbase transaction with only 0-value outputs.</p>
