Binary gender (not to be confused with Wikipedia:Gender binary) refers to any system that treats gender as being a dichotomy, typically in the form of male and female. In a binary gender system, characteristics given to one gender are necessarily absent from the other.
One widespread instance of binary gender is sports: classifications exist for "men's" or "women's" sports. Due to the dichotomized nature of sporting classifications, intersex athletes such as Caster Semenya are often provided few if any opportunities to compete "fairly."
As civilization has advanced, infrastructure that encodes primitive understandings of gender into the technology we use everyday has been built. A common example can be seen in the interfaces of many web sites' gender drop-down menus.
There is currently no technical standard that recognizes gender variance, although there is one that recognizes the Wikipedia:gender binary. Wikipedia:ISO 5218, entitled Information technology — Codes for the representation of human sexes contains 4 mutually exclusive options. These are:
- 0 = not known
- 1 = male
- 2 = female
- 9 = not applicable