Until now Facebook users have had to choose "male" or "female" as a gender when signing up for an account, but from today people will be able to select one of 50 options including "intersex" and "androgynous".
The site also allows users to select a gender-neutral pronoun, so the site would suggest to friends that they "wish them a happy birthday" rather than "wish him a happy birthday".
Facebook software engineer Brielle Harrison, who helped implement the changes and is herself undergoing gender transformation from male to female, told AP: "There's going to be a lot of people for whom this is going to mean nothing, but for the few it does impact, it means the world.
"All too often transgender people like myself and other gender nonconforming people are given this binary option, do you want to be male or female? What is your gender? And it's kind of disheartening because none of those let us tell others who we really are.
"This really changes that, and for the first time I get to go to the site and specify to all the people I know what my gender is."
The question is , which one of the following are you?
The list of 50 gender options in full
Female to Male
Male to Female
Source: The Telegraph