Subject: Re: [bitcoin-dev] [BIP Draft] Allow zero value OP_RETURN in Payment Protocol

From: Thomas Kerin <[email-masked]>
Date: Tue, 26 Jan 2016 16:19:18 +0000

On 26/01/16 03:30, Toby Padilla via bitcoin-dev wrote:
> There are already valid use cases for OP_RETURN, it only makes sense
> to fully support the feature. The only reason it's not supported now
> is because the Payments protocol came before OP_RETURN.
>
You keep saying OP_RETURN is new, but it has been there from day one.
It's purpose is causing script execution to end if encountered.

Since then, we have tolerated putting pushdata's after it, and even
raised the limit for the size of this data. It still doesn't mean every
proposal has to be rewritten to cater for a new allowance we give
OP_RETURN.

> I've also been exploring this area with key.run
> (https://git.playgrub.com/toby/keyrun) and want the functionality for
> voting based on aggregate OP_RETURN value. *Not* to store data on the
> blockchain, but to associate content pointers with transactions.
>
> I think that since OP_RETURN has already been approved and supported
> it doesn't make much sense for me to have to re-defend it from scratch
> here.

I'd generally agree with Luke. Removing the cost of this hurts bitcoin,
and ironically, your application to a certain degree. Just because you
can do a thing one way, it doesn't mean you should. Especially if your
applications success depends on people spamming OP_RETURN hashes of
every torrent they like.