I think you've seriously misunderstood the system I described. I'm saying we need first and foremost a standard for communicating such tags. It wouldn't dictate any categories, merely provide a framework for communicating any number of arbitrary categories. It would be immediately useful for the same groups that publish whitelists by providing a standard interoperable way for anyone to communicate categorizations.

Separately, I'm suggesting that the self reporting of certain categories be given legal significance and mandated. Such as porn.

I never said anything about burdening the ISP. Only the publisher, and when you consider the "burden" of self categorizing a few legally defined categories that for the most part already exist I really don't see an issue. What did you think these ID law proposals were for if not restricting access to various legally defined categories?