As to discovery: You use a link rel=amphtml tag on the canonical and then point the AMP file back via a link rel=canonical
They can, of course, be the same file if your AMP file is the canonical.
Is it worth having a doctype then? I don't see the logic in adding a description of a validator you then deliberately break.
> As to discovery: You use a link rel=amphtml tag on the canonical and then point the AMP file back via a link rel=canonical
Ah thanks. I'm not a huge fan of having two urls for the same resource, but this is at least some way of linking things.
https://developer.mozilla.org/en-US/docs/Quirks_Mode_and_Sta...
> The doctype keeps the browser in standards mode
Yes, I'm following that. It keeps it in standards mode because it's saying "Hey, this page is HTML5" and browsers can say "Oh good, a modern standards compliant website, this should be just fine"
What I mean is that these AMP pages are not valid HTML5. I don't like the idea of adding a tag which says "this is valid HTML5" when it isn't, just so that there is a side effect of changing the rendering mode that browsers use.
This sort of "same content, different view" feels like it's what content-type was designed to solve.