Babies born with characteristics that are neither exclusively male nor exclusively female have long been subject to sex assignment surgery as infants. In many cases, the biological sex chosen by the surgeon does not match the gender identity of the patient once awareness or adolescence is reached.
The law allows such infants to choose for themselves later in life whether to identify as male or female and consent to medical treatments appropriate to their choice.
The law also allows those assigned a third gender at birth to remain outside the gender binary if they choose, though passports and other documents still require a male or female designation.
Earlier this year, Australia became the first country in the world to introduce legal guidelines for gender recognition.
There, individuals have "the option to select M (male), F (female) or X (Indeterminate/Intersex/Unspecified)" on all personal documents. Individuals may opt into the third gender category regardless of whether they have undergone surgery or hormone therapy.
The Australian legislation also protects "intersex status" alongside other protected statuses including sex and race.
Human rights organizations continue to make headway on the issue in Europe, as other countries including Finland attempt to adopt new gender guidelines.
The Swiss National Advisory Commission on Biomedical Ethics apologized last year for past treatment of intersex individuals, calling for "an end to surgery for psychosocial reasons."
The group also halted non-trivial treatment until a child can consent, and the policy is enforced with criminal sanctions.
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