The policy explains that, for all disciplines on the sports programme of an IOC event, including the Olympic Games and for both individual and team sports, eligibility for any female category is limited to biological females. Eligibility for the female category is to be determined in the first instance by SRY gene screening to detect the absence or presence of the SRY gene. Based on scientific evidence, the IOC considers that the presence of the SRY gene is fixed throughout life and represents highly accurate evidence that an athlete has experienced male sex development. Furthermore, the IOC considers that SRY gene screening via saliva, cheek swab or blood sample is unintrusive compared to other possible methods.