I agree, but that's more of an information design problem; adding an explanation of the RFC 2119 key words (or rather, the facility to provide a clear, concise explanation) would be an interesting next step, along with the ability to remove things like ASCII art. Anything beyond that is well into the realm of textual editing, and I suspect that there would be a lot of crying foul, considering that one of the main aims of these RFCs is to avoid ambiguity and the need for interpretation (certainly beyond narrow, well-defined circumstances) – never mind that as you point out, specs are never implemented "correctly".