The United States military formerly excluded gay men, bisexuals, and lesbians from service. In 1993, the United States Congress passed, and President Bill Clinton signed a law instituting the policy commonly referred to as "Don't ask, don't tell" (DADT) which allowed gay, lesbian, and bisexual people to serve as long as they did not reveal their sexual orientation. Although there were isolated instances in which service personnel were met with limited success through lawsuits, efforts to end the ban on openly gay, lesbian, and bisexual people serving either legislatively, or through the courts initially proved unsuccessful.