I understand it the way it's written. I don't know what you're looking for here; jcrites is not staying that { HTML, CSS, JS } are prerequisites to REST. They

I understand it the way it's written. I don't know what you're looking for here; jcrites is not staying that { HTML, CSS, JS } are prerequisites to REST. They're giving examples of standard media types. If there are other media types for which it is possible to do REST, then those are acceptable, too, of course. But HTML is not a requirement.