Best practices are supposed to be just that, the best that one can do in a given situation. According to the Williams Record, the school paper of Williams College, the Trans* Inclusion Committee has hit upon just the thing when addressing a group of people. Don’t call them Mr., or Ms., instead call them “Mx.”
Maybe the “x” stands for unknown, or simply “this is too hard to figure out so we used an x to mark the spot.” Perhaps they could have simplified to “Hey You.” Since “you” is either singular or plural, it could apply to all people, no matter what they think they are, and no matter how many they believe they might be (for people with multiple identities).
The Trans* Inclusion Committee is part of the Office of Institutional Diversity and Equity, so they couldn’t just sit around and let Mr. and Ms. go.
There’s no word on how this moves forward the cause of higher education or the search for truth.