Norma relacionada
Practice Relating to Rule 42. Works and Installations Containing Dangerous Forces
Guinea’s Soldier’s Manual (2010), under the heading “Distinctive signs” and in a section on “Dams, dykes, [and] nuclear power plants”, shows a sign consisting of a group of three bright orange circles placed on the same axis and states: “Respect … objects marked with these signs.” 
Guinea, Soldier’s Manual, Ministry of National Defence, 2010, p. 11.