Gender markers

Gender markers are data points that show the gender of a person on a document (such as passport, driver's license, insurance card, birth certificate, etc) or in a computer system (such as an employee database, electronic health record, etc). Sometimes this data point is called "Sex" instead of "Gender".

The standard common gender markers are M for male and F for female. Other gender markers (which are not always available) include U for unspecified, O for other, and X for a nonbinary gender.

Some transgender and nonbinary activists hold the view that gender markers are unnecessary and should be done away with.