Transgender activists have hailed a decision by Facebook to increase its range of gender options to more than 50 as a "big advance".
The social network issued an update on Thursday which vastly extended the range of options with which users can identify.
The options include terms including "bi-gender", "transgender", "androgynous" and "transsexual".
In total there are now 56 individual gender options, a list drawn up in association with activists and rights groups.
Facebook also allows users to pick which pronoun they want to be addressed by - "he", "she" or "they". The site, which has 1.15 billion active monthly users, will also let users continue to keep their gender information private if they wish.
At first the new options are only available in US English, but will be customised for other languages in the future.
"We collaborated with our Network of Support, a group of leading LGBT advocacy organizations, to offer an extensive list of gender identities that many people use to describe themselves. Moreover, people who select a custom gender will now have the ability to choose the pronoun they’d like to be referred to publicly — male (he/his), female (she/her) or neutral (they/their).
We also have added the ability for people to control the audience with whom they want to share their custom gender. We recognize that some people face challenges sharing their true gender identity with others, and this setting."
“While to many this change may not mean much, for those it affects it means a great deal,” said a Facebook publicist. “We see this as one more way we can make Facebook a place where people can express their authentic identity.”
In response the San Francisco-based Transgender Law Center, based near to Facebook's HQ, said many people would be "thrilled" by the news.
Other activists on Facebook's site said the service should now increase its range of options for relationship status and type, and look for more ways to become even more inclusive. One example is that it's still not possible to choose anything other than "son" or "daughter" when describing your children, which some users feel is not broad enough.Suggest a correction