Hasan Ali in The Nation:
For centuries, intersex people—those who possess both male and female sexual organs—and those assigned male at birth who have subsequently identified as women have left their homes and joined third-gender communities, where they have been able to express their femininity without fear of persecution. These societies are organized around a guru-chela (master-disciple) system of kinship and have their own rules, rituals, and dispute resolution mechanisms. In Pakistan, the terms used to describe people who belong to these communities are varied and sometimes used interchangeably. Most common among them are the words hijra and khawaja sira, two historically distinct groups who are conflated in the modern day.
More here.