#2 25 Aug 2015 23:08
@chris_of_arabia the gender info is saved into the
T_users.user_gender field which is defined as CHAR(1), and there are no restrictictions at database level for the possible values. Limitations are stablished in the code, so the only valid values that you can send through the interface (back and front-office) are "M" and "F".
As an idea, Facebook let users stablish a third gender: "Custom". After selecting that option, a text field is enabled and I think they are able to type in any value: i.e.: Vulcanian :D