- Constructors on the global object, like
- What static methods are on that constructor, like
- What methods are on the prototype, like
- What properties are only on instances, like
Based on this information, it would be possible to generate feature detection tests and cross-check the data in MDN's browser-compat-data project.
I think much of it could be inferred from just the spec's headings, but if the work of turning the spec into a dataset like that has already been done, that would be nice to take a look at.