We've had that twenty years ago, in Internet Explorer no less [1]. It just never gained traction, likely because it was quite convoluted. [1] https://en.wikipe

We've had that twenty years ago, in Internet Explorer no less [1]. It just never gained traction, likely because it was quite convoluted. [1] https://en.wikipedia.org/wiki/P3P https://en.wikipedia.org/wiki/P3P