Yazidi social rules are strict and endogamous: marriage outside the community is forbidden, and marriage across the three castes (sheikh, pir, and the lay murid) is also forbidden. There is no conversion in either direction. The rules read as harsh from outside and are understood inside as the mechanism by which a small, repeatedly attacked people has survived — though the community has had to confront them directly since 2014, when the spiritual council took the unprecedented step of accepting back women who had been enslaved and forcibly converted.