REST as defined in the original papers, REST as defined by your link, and REST as actually used in practice are all somewhat different. Even in your link it is

REST as defined in the original papers, REST as defined by your link, and REST as actually used in practice are all somewhat different. Even in your link it is plainly obvious that there is no provision for documenting what an endpoint does, or how to find what endpoint maps to something, or even how to query this magical introspective API to figure out what further requests you need to make.