Sex characteristics refers to an individual's physical sexual features. It also refers to an attribute defined in law for the purposes of protecting individuals from discrimination due to their sexual features. The attribute of sex characteristics was first defined in national law in Malta, in 2015.
Physical sex characteristics include primary sex characteristics and secondary sex characteristics. A primary sexual characteristic, as narrowly defined, is any anatomical part of the body involved in sexual reproduction and constituting the reproductive system in a complex organism, especially the external sex organs; the external sex organs are also commonly referred to as the genitalia or genitals.
Secondary sex characteristics are features that appear at sexual maturity in animals and during puberty in humans, especially the sexually dimorphic phenotypic traits that distinguish the sexes of a species, but that, unlike the sex organs, are not directly part of the reproductive system.
In a wide-ranging analysis on intersex human rights and health issues, the Council of Europe published an Issue Paper entitled Human rights and intersex people in May 2015. The document highlighted an historic lack of attention to intersex human rights, stating that current social and biomedical understandings of sex and gender make intersex people "especially vulnerable" to human rights breaches. The report cited previous reports from San Franscisco, the Swiss National Advisory Commission on Biomedical Ethics and the Australian Senate. The Commissioner for Human Rights recommended that Member States of the Council of Europe protect intersex citizens on grounds of "sex characteristics", or otherwise protect intersex persons on grounds of sex or gender: