General Philosophy Levels of HTTP Nirvana, or POST Vs. New Methods . Why IDs need to be Opaque Tokens . Larry Masinter's Excellent Advice on how to structure early protocol Drafts . Versioning, Collections and Sources .
Some people have different views.
However, Yaron is the only person who has taken the time to write an extensive set of posts about the design rationale. They provide a lot of insight, even if some people disagree.