It’s true that we can look at most websites and generally agree on which ones are “light” (e.g. HN or Wikipedia) and which ones are “heavy” (e.g. Gmail or Sound

It’s true that we can look at most websites and generally agree on which ones are “light” (e.g. HN or Wikipedia) and which ones are “heavy” (e.g. Gmail or SoundCloud), but that doesn’t mean it would be easy to define a specification that would allow all and only light websites to be built. An extremely light and content-focused spec like Gopher would exclude a lot of websites that we would consider light. Terms used to describe light subsets of web capabilities, like “DHTML,” do not appear to be well defined. My initial attempt would be to exclude XHR/fetch, dynamic URL/history manipulation (window.history), and loading resources from other domains. But the latter would probably exclude things I don’t oppose (like CDNs) and things I don’t necessarily support but which would surely drastically impede adoption (like third party ads/analytics services). Can you propose a better and more viable spec?