Under the order of the guidelines, a 16-year-old high-school junior who says that he believes he is a girl has the right to use the girls bathroom and locker room. (But before boys who are unconfused about their gender get any bright ideas, the guidelines are ready: The transgender feelings must be “sincerely held.” School staff can challenge anyone who seems to be making the assertion for “some improper purpose.”) If a female student feels uncomfortable and objects to the boy’s presence when she is in the bathroom, the rules say, the complaint “is not a reason to deny access to the transgender student.”

It is a given that nearly all teenage girls will feel deeply uncomfortable having an anatomical male of any sort using the same bathroom or locker-room shower. That is the reality of human life, and no young woman should be forced to endure such embarrassment. As for an anatomical but transgender girl showering in the boys locker room, that hardly bears contemplating.

At least the guidelines seem to recognize the trouble they invite: “The Department strongly recommends that districts include an appropriate number of gender-neutral restrooms commensurate with the size of the school, and at least one gender-neutral changing facility, into the design of new schools and school renovations.”