Four R.A.V. Exceptions (to prohibition on regulations of a content-based subcategory of a proscribable class of speech)

1) "[T]he basis for the content discrimination consists entirely of the very reason the entire class of speech at issue is proscribable."

2) ["T]he subclass happens to be associated with particular 'secondary effects' of the speech so that the regulation is 'justified without reference to the content of the . . .  speech.'"

3) "[A] particular content-based subcategory of a proscribable class of speech can be swept up incidentally within the reach of a statute directed at conduct rather than speech." This is because "[w]here the government does not target conduct on the basis of its expressive content, acts are not shielded from regulation merely because they express a discriminatory idea or philosophy." (Example: Title VII’s general prohibition against sexual discrimination in employment practices). 

4) "[S]o long as the nature of the content discrimination is such that there is no realistic possibility that official suppression of ideas is afoot."