I have noticed that Google uses this server header:
As they are clever guys, that must make sense for a reason.
Unfortunately it seems that there is nearly no information about it on the web. I can find that Chrome is supporting it, but not the sense of it …
Does anybody know this header and its effect?
So if I use http (and not https) it would not have any effect for the Chrome browser users who are able to use this protocol.
Conclusion: Currently not worth thinking about it.
Yeah, ignore it. The protocol doesn’t exist in any form that you’d be able to use and advertising the header would probably just break or slow down (while the browser falls back) any browsing on your pages.