In Sweden, sex education was established in 1921 for secondary education and in 1942 for all grades. The subject is usually started in kindergarten and continues cumulatively throughout the student's entire schooling. This sexual education is incorporated into different subjects such as biology and history. The Swedish Association for Sexuality Education (RFSU) has a sex education that emphasizes "sexual diversity, freedom and enjoyment", and the RFSU collaborate frequently with government organizations such as the National Institute of Public Health. Alongside this emphasis of sexual diversity, Swedish sex education has equal incorporations of lesbian and gay sexuality as well as heterosexual sexuality. They provide knowledge about masturbation, oral and anal sex as well as heterosexual, genital intercourse.