Lambda

Lambda (Greek Λάμβδα) is the 11th letter of the Greek alphabet - upper case Λ, lower case λ - corresponding to the Roman letter L. A lower case λ has been used internationally as a symbol for gay liberation.

The symbol was originally chosen by the Gay Activists Alliance of New York in 1970. In December 1974, the lambda was officially declared the international symbol for gay and lesbian rights by the International Gay Rights Congress in Edinburgh.

There have been various explanations as to why this particular letter was chosen.