https://gizmodo.com/airlines-will-offer-new-gender-options-beyond-male-and-1832687550

Many U.S. airlines say they’re in the process of updating their booking systems in order to allow non-binary customers to use pronouns other than “male” or “female.”

United Continental Holdings, which owns United Airlines, said that it will allow alternative gender options that include “U” for “undisclosed” and “X” for “unspecified,” the Wall Street Journal reported Saturday. It will also add Mx. as an alternative to Mr. or Ms., the Journal said, with the changes coming to United’s booking platform in the coming weeks.