Just 8 days after the Carnation Revolution, Serzedelo co-authored the manifesto "Freedom for the Sexual Minorities", which was written by the newly established "Homosexual Movement for the Revolutionary Action" and published on 13 May 1974 in the daily newspapers Diário de Lisboa and Diário de Notícias. It is considered the foundational document for the LGBTI cause in Portugal and had great repercussion at that time. From that point on, Serzedelo became involved in various causes and organizations, although he is still best known for his role in the LGBTI cause.
