Thank you... I've updated.

New schemes should probably NOT be based on the current one.

Fair enough... I still think there are those who would still like an existing sign/verify BIP to reference.

On Thu, Dec 21, 2017 at 5:09 PM, Luke Dashjr <luke@dashjr.org> wrote:
On Thursday 21 December 2017 10:26:25 PM Dan Bryant via bitcoin-dev wrote:
> https://github.com/brianddk/bips/blob/legacysignverify/bip-0xyz.mediawiki

It's not even correct... Your first "verify message" step is not possible; you
can't get a public key from an address.

What is actually done, is using the signature + message to perform key
recovery, to extract the public key of the signer, and then hashing that and
comparing it to the address provided.

> Although this is a well established functionality, it has never been
> published in a BIP.  My proposal is simply to provide a reference point for
> future expansion of these capabilities into new address schemes.

New schemes should probably NOT be based on the current one.

Luke