Suggestion: Add Acceptance Size to the Coinbase Text (BUIP005)


New Member
Jan 4, 2016
I think one of the most important factor for miners is: to calculate how much is the risk to mine bigger blocks which other miners will accept and mine on top of it.

Coinbase Text in BUIP005 only shows what size miners want to mine, but doesn't show at what size he will accept it right away and mining on top of it.

So I would suggest to replace the "Maximum Generate Size" with "Maximum Acceptance Size (AS)" Combining with the Proposed Activation Block Height (ABH), this will indicate miner willing to accept and mine on top of any block that not bigger than AS after ABH. This is for the coinbase text only, not for the user-agent, and miner does't need to show the Excessive Block Size.

Knowing how big the block that other miners will accept is much more useful information than how much they start to produce.


Staff member
Aug 22, 2015
I have been thinking about this.
One thing we can't do is change the meaning of anything in BUIP001 or BUIP005 as they are long voted on, in the software, and now being looked at by developers outside BU.
Adding an extra informational value is feasible i.e. maximum acceptance size, which does not exist.

Looking at an existing theoretical example: /MG2.0/EB3.5/AD4/FG2.5@3/
Here the miner is mining up to 2MB but is signalling a future size of 2.5MB at the 3rd upcoming multiple of 12,000 blocks from the current block height (i.e. the block height where this text appears).

So, if one asks "What size will the miner accept right away" then it is 3.5MB currently, but mining 2.5MB at an upcoming specified block height. I am not sure that maximum acceptance size would add anything further. If the miner was OK with blocks up to 2.5 right now then the MG would already be 2.5.

Am I missing something more nuanced in your proposal?
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New Member
Jan 4, 2016
Maximum Generate Size is may not the same as Maximum Acceptance Size. With Maximum Acceptance Size, miner can choose to stay to generate block at 1MB (Maximum Generate Size), but willing to mining on top of new blocks (found by others) that's under Maximum Acceptance Size.

Roy Badami

Active Member
Dec 27, 2015
@xd1gital: EB is already the maximum blocksize you will accept. If a block is <=EB you accept it right away. If it is >EB, you wait AH blocks before accepting it. MG is indeed much less interesting than EB, and BU doesn't actually advertise it in the coinbase. Advertising the current MG is somewhat pointless, anyway, since you can easily see what size blocks a miner is actually generating.

It's true that BUIP 005 lacks a means of advertising a future value for EB. However I would argue that FG effectively serves this purpose, since you must regard blocks you generate as valid.

I'd be in favour of redefining FG (which isn't actively being advertised by any miners atm) to mean "future EB" rather than "future MG", I think.