Just change the message in your wiki if you want it typograph correct.

I would suggest to remove the hyphen or dash completly, it is not needed. But that is another discusion, see T14472

• Changing this in "my wiki" means changing it in hundreds of wikis.
• This doesn't affect my own signature, because I don't click the buttons that use this. I just type the wikitext code for signatures manually.
• I'd be happy with removing it (=the hyphens/whatever precedes the actual signature) completely. However, editors from a couple of wikis have told me recently that signatures are "supposed to" have the decorative line that is provided through this message,[1] and that the absence of a dash is how they know when an editor is new or otherwise undesirable.[2]

[1] In addition to this, I know at least one that would prefer a slash, /, which is used on some paper-based documents to indicate that a signature belongs in that space.

[2] I'm not sure why they conclude that knowing how to type the wikitext for a signature manually (i.e., ~~~~) instead of clicking the button in the toolbar demonstrates that someone is inexperienced, but it probably would be a reasonably reliable indicator that the editor has an English-language keyboard.

Note that the two dashes are inherited from https://tools.ietf.org/html/rfc3676#section-4.3. This is a rather silly reason, but if you know Wikipedians well enough, those silly reasons are those which will cause the most awful discussions if you want to change them.

Are you sure about that? Because if so, then we're doing it wrong. RFC 3676 specifies "DASH DASH SP" (the space is not optional), and the common implementation is this:

--
My Name
e-mail address

rather than what we're doing, which is --MyName.

Obviously, the "Usenet Signature Convention" is technically irrelevant outside of e-mail/Usenet contexts, but I agree with your assessment about the social implications, if some people believe that this is the source.

At least that explanation is what I've heard repeatedly, and as I said, it is a rather silly reason.
On German Wikipedia, there exists a user script (https://de.wikipedia.org/wiki/Benutzer:Jowereit/Typografie) to turn two dashes into an EM-dash (among other things), which actually has an option not to do so for the dashes in front of the signature, defaulting to true.

@Umherirrender: I'm wondering whether you are bold enough to just try this change locally in de.wikipedia, just to see if a) the change is noticed at all, and b) whether there are objections against it.
If people complain, you could just revert it and explain you only wanted to collect data to make sure this task is not only founded on assumptions how users will react to the proposed change, and if they don't, it's probably safe to change it globally.

In T164863#3262007, @Schnark wrote:

@Umherirrender: I'm wondering whether you are bold enough to just try this change locally in de.wikipedia, just to see if a) the change is noticed at all, and b) whether there are objections against it.
If people complain, you could just revert it and explain you only wanted to collect data to make sure this task is not only founded on assumptions how users will react to the proposed change, and if they don't, it's probably safe to change it globally.

I removed the hypen back in 2012 from edit toolbar: https://de.wikipedia.org/w/index.php?title=MediaWiki:Common.js&diff=prev&oldid=106127402
The (long) discussion (german) can be found here: https://de.wikipedia.org/wiki/Hilfe_Diskussion:Signatur/Archiv/1#Standardsignatur
5 years later the chance to get the same discussion with the same users is very high

(sig-text was added 2016 with https://gerrit.wikimedia.org/r/#/c/259061/, so I had to use javascript to change it)

Schnark, are you asking Umherirrender to consider removing the hyphens entirely (which he did in 2012 and doesn't expect to be any more popular now), or to substitute a proper dash, or to change the default on that script?

I'd like to see what happens when MediaWiki:sig-text is changed locally to –~~~~ with a proper EN dash, like you proposed, just to see whether my worries that there will be huge complaints about the change are correct (in which case this task needs more discussion), or whether the change will just go unnoticed (in which case this task can easily be solved globally).

If you want to try an experiment, you could, for example, change the default message, provide a gadget which does basically mw.config.set('mw.msg.wikieditor', '--~~\~~'); (this should change signature button in WikiEditor, don’t know about VE) and announce this change on your community forum to see how many people would revert to the old style (via Special:GadgetUsage after a month or two). We can try to get this experiment going on several wikis and get some feedback on this as a measure to test if this will be noticeable by users at large.

Please consider though that typographic practices are different across languages (e. g. in Russian it would be — ~~~~) and this should be taken in account. -- is good at one thing − it is not natural for any language :–)