[myfonj]

> Historically, […] no relevant browser has ever implemented SGML […] NET

I can probably confirm that "relevant" part of this claim for the times spanning from the first decade of 2000s, but I still desperately (in a way) seek information whether ANY even niche and obscure application that consumed "HTML" treated the NET as specified back then. I am quite certain W3C Validator did (that Mathias' article proves that, after all) and that Amaya might have do that, since it was a reference implementation from the same spec body, IIRC, but cannot swear on that.

Have anybody here have a clearer recollection of that times, or even some evidence?

I still find it strange such feature had such prominent space in the specs back then, but practically nowhere else.

[JimDabell]

EMACS/W3 originally supported SHORTTAG NET but was “fixed” to remove support. In practical terms, mainstream browsers couldn’t afford to parse SHORTTAG NET properly because it was very common to leave attribute values unquoted. You can leave some values unquoted, but not ones with slashes in. So the very common error <a href=http://xn--rvg would not get parsed as the author expected if SHORTTAG NET was enabled.

This is the earliest reference I could locate easily, from the www-html mailing list:

https://lists.w3.org/Archives/Public/www-html/2002Nov/0057.h...

You’ll be able to find more if you go trawling through USENET archives of places like comp.infosystems.www.authoring.html from 25–30 years ago, but it was a fairly niche subject even back then.

I think there were a couple of other niche tools that supported it, but I don’t remember the details after all this time.

[JimDabell]

I believe this is the exact change where support for SHORTTAG NET was removed from EMACS/W3 in order to support XHTML better:

https://github.com/emacsmirror/w3/commit/68af7c107dcbe194e30...

[myfonj]

Thanks! That's actually really valuable insight and seems to be a promising start for a interesting investigation

I'd even say that from a glance, EMACS ("W3" browser in it) seems like possibly hugely relevant application, actually. Will look into it.

[JimDabell]

If you really want to, you could check out Evolt’s browser archive:

https://browsers.evolt.org

It‘s got over a hundred ancient web browsers. I suspect none of them support SHORTTAG NET though.

[myfonj]

Good idea. I remember I have done some research about this in the past when I tried to trace historical arguments for the infamous "should there be a space before slash in void tags for the best compatibility"

    <br/> vs <br /> (vs <br>)

discussion, but didn't get much far then (https://stackoverflow.com/a/30880386/540955).