I'm not even sure that this paragraph makes sense.  What are you trying to say?

I think that what you want to say is that "HTTP/2.0 streams and framing layer errors result in stream or connection errors (see relevant sections).  Application layer errors are dealt with by the application layer.  For example, a request missing mandatory header fields is an HTTP problem and results in an HTTP 4xx error; extra-long frames is a framing layer problem and results in a FRAME_TOO_LARGE error."

However, I don't think that you need to provide that guidance here.  If it is going to be provided, it should be provided outside of this mapping - in the error handling section.  Besides, it's a separable thing, this commit already has more in it than I'm really comfortable with (and I'm not done reviewing it yet).