The small group of variable stars called R Corona Borealis (RCB) has been changing in number as much as in composition according to the evolution of the knowledge of its fundamental properties. V731 Sco is one of the stars whose membership to the RVB group is considered doubtful in the 3rd. and 4th. editions of the GCVS. In order to establish its membership to the RCB group it was necessary a proper identification of the star.Asociación Argentina de Astronomía