Slash later spread to other fan groups, first Starsky and Hutch, Blake's 7, and The Professionals, then many others, eventually creating a fandom based on the concept of slash. For a time, both slash and K/S (for 'Kirk/Spock') were used interchangeably. The name arises from the use of the slash symbol (/) in mentions in the late '70s of K/S (meaning stories where Kirk and Spock had a romantic relationship), as compared to the ampersand (&) conventionally used for K&S or Kirk and Spock friendship fiction.
It is commonly believed that slash fan fiction originated during the late 1970s, within the Star Trek: The Original Series fan fiction fandom, starting with ' Kirk/Spock' stories generally authored by female fans of the series.
