What pseudonym is Mark Felt more widely known as?

In 2005, at age 91, Felt revealed to "Vanity Fair" magazine that during his tenure as Deputy Director of the FBI he had been the anonymous source known as "Deep Throat", who provided "The Washington Post" reporters Bob Woodward and Carl Bernstein with critical information about the Watergate scandal, which ultimately led to the resignation of President Richard Nixon in 1974.