In 19th-century England, green indicated homosexual affiliations, as popularized by gay author Oscar Wilde, who often wore a green carnation on his lapel. The gay rights organization Lambda Legal and the American Lambda Literary Foundation derive their names from this symbol. The lambda became associated with Gay Liberation, and in December 1974, it was officially declared the international symbol for gay and lesbian rights by the International Gay Rights Congress in Edinburgh, Scotland. The alliance's literature states that Doerr chose the symbol specifically for its denotative meaning in the context of chemistry and physics: 'a complete exchange of energy–that moment or span of time witness to absolute activity'. In 1970, graphic designer Tom Doerr selected the lower-case Greek letter lambda (λ) to be the symbol of the New York chapter of the Gay Activists Alliance. The symbols for the female (♀), male (♂), and combined male-female (⚦) combined (⚧) are used to represent transgender people, as is the simple combined symbol ⚦. These symbols first appeared in the 1970s. Two interlocking female symbols (⚢) represent a lesbian or the lesbian community, and two interlocking male symbols (⚣) a gay male or the gay male community. Lesbian and gay interlocked gender sex symbols
