I have never actually seen anyone cite 90.4 but I have seen guys say "That is the way I read that section" and come up with a plausible explanation. That gap between different readings can get pretty wide, that is why I think people getting together on these BBs and talking things out is very valuable. The local trade groups are good about this too.
I still see different rules in the various jurisdictions in spite of a state code.
It would be great if everyone was using the same code