Amphtml: Is there any specific reason to disallow HTML <progress> Tag?

[faelgabriel]

Is there any specific reason to disallow HTML <progress> Tag?
It's a HTML5 element, is there an issue to allow this tag?

[jridgewell]

/to @Gregable

[Gregable]

I don't see any reason why not. I'm unsure why it was missed. I'll add it.

[Gregable]

OK, now I see why it was originally left out. It's part of section 4.10 (forms) of the HTML5 spec. Forms weren't originally supported in AMP and so form related elements were also left out.

There is no reason not to add them in at this point. I'll also add <meter> and <output> while at it.

[jridgewell]

@Gregable: Remember to ban <output>s with special name properties.

[Gregable]

Yep, @honeybadgerdontcare reminded me of this one as I was implementing. Change is simple, but it'll be a while before released.

[honeybadgerdontcare]

This is now live in prod.