user7214: I understand that, with BIP 100 as suggested by Jeff Garzik, in the first step the maximum block size can be increased from (then, after the hard fork) 2 MByte to at most double of that, so 4 MByte - without a hard fork. Depending on the miner's votes (counted for 12.000 blocks, 75% majority necessary) the block size may be increased further.
How can I, as a user start the voting process? What if I'm a miner? How do I determine the new maximum block size? Can two votes for 3 MByte and 4 MByte run in parallel?

user7214: Gregory Maxwell in IRC:

the scheme would have the pariticiants specify the size they want, and
  at the end the period the smallest 25% would be tossed and the
  smallest remaining would be used.

So in each block there would be a field, initially set to 2 MByte. A miner is free to set any value (up to 2x the current limit).
Assuming we have the following values set in the last 12,000 blocks:

20% 2 MByte
20% 3 MByte
60% 4 MByte

Then, because only 60% want 4 MByte but 80% agree to have 3 MByte, the limit is increased to 3 MByte.
There would be a new vote every 12,000 blocks, and a decrease also would be possible if that is what the miners want.

7214: <p>I understand that, with BIP 100 as suggested by Jeff Garzik, in the first step the maximum block size can be increased from (then, after the hard fork) 2 MByte to at most double of that, so 4 MByte - without a hard fork. Depending on the miner's votes (counted for 12.000 blocks, 75% majority necessary) the block size may be increased further.</p>

<p>How can I, as a user start the voting process? What if I'm a miner? How do I determine the new maximum block size? Can two votes for 3 MByte and 4 MByte run in parallel?</p>
 7214: <p>Gregory Maxwell in IRC:</p>

<blockquote>
  <p>the scheme would have the pariticiants specify the size they want, and
  at the end the period the smallest 25% would be tossed and the
  smallest remaining would be used.</p>
</blockquote>

<p>So in each block there would be a field, initially set to 2 MByte. A miner is free to set any value (up to 2x the current limit).
Assuming we have the following values set in the last 12,000 blocks:</p>

<ul>
<li>20% 2 MByte</li>
<li>20% 3 MByte</li>
<li>60% 4 MByte</li>
</ul>

<p>Then, because only 60% want 4 MByte but 80% agree to have 3 MByte, the limit is increased to 3 MByte.</p>

<p>There would be a new vote every 12,000 blocks, and a decrease also would be possible if that is what the miners want.</p>
