My favorite reference:
The phrase "MIGHT" conveys a requirement in an intentionally stealthy fashion, to facilitate product differentiation (cf. "COULD" above).For example: "In the case of audio and different "m" lines for different codecs, an implementation might decide to act as a mixer with the different incoming RTP sessions, which is the correct behavior."
I just adore that passive aggressive "... which is the correct behavior" and would love to hear the anecdote for why the editor snuck that in there and how many chairs were thrown during the meeting.