When is a woman not a woman? In some traditions, a female human being is considered to be a woman when she marries, regardless of her age. In certain communities, first menstruation is taken as a sign of womanhood. In other societies, the age when childhood ends shifts with changes in fashion, pop culture, and sexual imagery. There are other thresholds too, enshrined in national laws relating to the age of marriage, of sexual consent, and of legal responsibility. These differ among countries and within countries, so that a 17-year-old in some countries may be old enough to marry, but not old enough to buy alcohol or take out a mortgage. The United Nations Convention on the Rights of the Child (1989) gives us a benchmark for when childhood ends: all people under the age of 18 are children. This is not to deny 17- year-old females their right to be considered and to be called 'women' if they wish. It does not suggest that the group often labelled 'adolescents' or 'teenagers' or 'young people' is immature. It is a way to remind ourselves that anyone under the age of 18, regardless of other thresholds and labels, has a right to special protection. This is particularly important in relation to children and sexual activity.