From: Luke Dashjr <luke@dashjr.org>
To: Sjors Provoost <sjors@sprovoost.nl>
Date: Tue, 5 Dec 2017 19:39:32 +0000
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Message-Id: <201712051939.33238.luke@dashjr.org>
Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>,
	Matt Corallo <matt@chaincode.com>
Subject: Re: [bitcoin-dev] BIP-21 amendment proposal: -no125
Precedence: list

On Tuesday 05 December 2017 7:24:04 PM Sjors Provoost wrote:
> I recently submitted a pull request that would turn on RBF by default,
> which triggered some discussion [2]. To ease the transition for merchants
> who are reluctant to see their customers use RBF, Matt Corallo suggested
> that wallets honor a no125=1 flag.
> 
> So a BIP-21 URI would look like this:
> bitcoin:175t...45W?amount=20.3&no125=1
> 
> When this flag is set, wallets should not use RBF, regardless of their
> default, unless the user explicitly overrides the merchant's preference.

This seems counterproductive. There is no reason to ever avoid the RBF flag. 
I'm not aware of any evidence it even reduces risk of, and it certainly 
doesn't prevent double spending. Plenty of miners allow RBF regardless of the 
flag, and malicious double spending doesn't benefit much from RBF in any case.

> P.S. I'd similarly suggest adding a bech32 param, but that's for another
> discussion

Bech32 addresses are just normal addresses. What need is there for a param?

Luke