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Date: Wed, 14 May 2025 15:54:55 +0000
To: Bitcoin Development Mailing List <bitcoindev@googlegroups.com>
From: "'Antoine Poinsot' via Bitcoin Development Mailing List" <bitcoindev@googlegroups.com>
Subject: [bitcoindev] Re: Relax OP_RETURN standardness restrictions
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Hi,

This proposal was heavily mediatized, and severe mischaracterizations of th=
e change being proposed led to genuine concerns among the community. A bett=
er communication from my part could have avoided unnecessary worries among =
bitcoiners and a lot of wasted time to everybody.

In an attempt to right this wrong, i have collected objections community me=
mbers have raised across the board (on Github, the Bitcoin development mail=
ing list, X, podcasts, at conferences, ..) to address them in a single post=
.

I just posted to Delving Bitcoin addressing all concerns and objections i c=
ould get my hands on: https://delvingbitcoin.org/t/addressing-community-con=
cerns-and-objections-regarding-my-recent-proposal-to-relax-bitcoin-cores-st=
andardness-limits-on-op-return-outputs/1697. These are actual objections an=
d concerns raised by community members, taken literally with little or no r=
eformulation to address the precise statement.

Antoine Poinsot
On Thursday, April 17th, 2025 at 2:52 PM, Antoine Poinsot <darosior@protonm=
ail.com> wrote:

> Hi,
>
> Standardness rules exist for 3 mains reasons: mitigate DoS vectors, provi=
de upgrade hooks, or as a nudge to deter some usages.
>
> Bitcoin Core will by default only relay and mine transactions with at mos=
t a single OP_RETURN output, with a scriptPubKey no larger than 83 bytes. T=
his standardness rule falls into the third category: it aims to mildly dete=
r data storage while still allowing a less harmful alternative than using n=
on-provably-unspendable outputs.
>
> Developers are now designing constructions that work around these limitat=
ions. An example is Clementine, the recently-announced Citrea bridge, which=
 uses unspendable Taproot outputs to store data in its "WatchtowerChallenge=
" transaction due to the standardness restrictions on the size of OP_RETURN=
s[^0]. Meanwhile, we have witnessed in recent years that the nudge is ineff=
ective to deter storing data onchain.
>
> Since the restrictions on the usage of OP_RETURN outputs encourage harmfu=
l practices while being ineffective in deterring unwanted usage, i propose =
to drop them. I suggest to start by lifting the restriction on the size of =
the scriptPubKey for OP_RETURN outputs, as a first minimal step to stop enc=
ouraging harmful behaviour, and to then proceed to lift the restriction on =
the number of OP_RETURN outputs per transactions.
>
> Antoine Poinsot
>
> [^0]: See section 6.1 of their whitepaper here https://citrea.xyz/clement=
ine_whitepaper.pdf

--=20
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<div style=3D"font-family: Arial, sans-serif; font-size: 14px;">Hi,</div><d=
iv style=3D"font-family: Arial, sans-serif; font-size: 14px;"><br></div><di=
v style=3D"font-family: Arial, sans-serif; font-size: 14px;">This proposal =
was heavily mediatized, and severe mischaracterizations of the change=20
being proposed led to genuine concerns among the community. A better=20
communication from my part could have avoided unnecessary worries among=20
bitcoiners and a lot of wasted time to everybody.<br></div><div style=3D"fo=
nt-family: Arial, sans-serif; font-size: 14px;"><br></div><div style=3D"fon=
t-family: Arial, sans-serif; font-size: 14px;">In an attempt to right this =
wrong, i have collected objections community
 members have raised across the board (on Github, the Bitcoin=20
development mailing list, X, podcasts, at conferences, ..) to address=20
them in a single post.</div><div style=3D"font-family: Arial, sans-serif; f=
ont-size: 14px;"><br></div><div style=3D"font-family: Arial, sans-serif; fo=
nt-size: 14px;">I just posted to Delving Bitcoin addressing all concerns an=
d objections i could get my hands on: <span><a target=3D"_blank" rel=3D"nor=
eferrer nofollow noopener" href=3D"https://delvingbitcoin.org/t/addressing-=
community-concerns-and-objections-regarding-my-recent-proposal-to-relax-bit=
coin-cores-standardness-limits-on-op-return-outputs/1697">https://delvingbi=
tcoin.org/t/addressing-community-concerns-and-objections-regarding-my-recen=
t-proposal-to-relax-bitcoin-cores-standardness-limits-on-op-return-outputs/=
1697</a></span>. These are actual objections and concerns raised by communi=
ty members,=20
taken literally with little or no reformulation to address the precise=20
statement.</div><div style=3D"font-family: Arial, sans-serif; font-size: 14=
px;"><br>Antoine Poinsot<br></div><div class=3D"protonmail_quote">
        On Thursday, April 17th, 2025 at 2:52 PM, Antoine Poinsot &lt;daros=
ior@protonmail.com&gt; wrote:<br>
        <blockquote class=3D"protonmail_quote" type=3D"cite">
            <div style=3D"font-family: Arial, sans-serif; font-size: 14px;"=
>
<div style=3D"font-family: Arial, sans-serif; font-size: 14px;" class=3D"pr=
otonmail_signature_block protonmail_signature_block-empty">
    <div class=3D"protonmail_signature_block-user protonmail_signature_bloc=
k-empty">

            </div>

            <div class=3D"protonmail_signature_block-proton protonmail_sign=
ature_block-empty">

            </div>
</div>
Hi,<br>
<br>
Standardness rules exist for 3 mains reasons: mitigate DoS vectors, provide=
 upgrade hooks, or as a nudge to deter some usages.</div><div style=3D"font=
-family: Arial, sans-serif; font-size: 14px;"><br></div><div style=3D"font-=
family: Arial, sans-serif; font-size: 14px;">Bitcoin Core will by default o=
nly relay and mine transactions with at most a single OP_RETURN output, wit=
h a scriptPubKey no larger than 83 bytes. <span>This standardness rule fall=
s into the third category: it aims to mildly deter data storage while still=
 allowing a less harmful alternative than using non-provably-unspendable ou=
tputs.</span></div><div style=3D"font-family: Arial, sans-serif; font-size:=
 14px;"><span><br></span></div><div style=3D"font-family: Arial, sans-serif=
; font-size: 14px;">Developers are now designing constructions that work ar=
ound these limitations. An example is Clementine, the recently-announced Ci=
trea bridge, which uses unspendable Taproot outputs to store data in its "W=
atchtowerChallenge" transaction due to the standardness restrictions on the=
 size of OP_RETURNs[^0]. Meanwhile, we have witnessed in recent years that =
the nudge is ineffective to deter storing data onchain.</div><div style=3D"=
font-family: Arial, sans-serif; font-size: 14px;"><br></div><div style=3D"f=
ont-family: Arial, sans-serif; font-size: 14px;">Since the restrictions on =
the usage of OP_RETURN outputs encourage harmful practices while being inef=
fective in deterring unwanted usage, i propose to drop them. I suggest to s=
tart by lifting the restriction on the size of the scriptPubKey for OP_RETU=
RN outputs, as a first minimal step to stop encouraging harmful behaviour, =
and to then proceed to lift the restriction on the number of OP_RETURN outp=
uts per transactions.<br></div><div style=3D"font-family: Arial, sans-serif=
; font-size: 14px;"><br></div><div style=3D"font-family: Arial, sans-serif;=
 font-size: 14px;">Antoine Poinsot<br></div><div style=3D"font-family: Aria=
l, sans-serif; font-size: 14px;"><br></div><div style=3D"font-family: Arial=
, sans-serif; font-size: 14px;">[^0]: See section 6.1 of their whitepaper h=
ere <span><a href=3D"https://citrea.xyz/clementine_whitepaper.pdf" rel=3D"n=
oreferrer nofollow noopener" target=3D"_blank">https://citrea.xyz/clementin=
e_whitepaper.pdf</a></span><br></div>
        </blockquote><br>
    </div>

<p></p>

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