Mafia families vary in their openness about recruitment and membership

Evidence

The fact that the Corleone family was unusually secretive is confirmed by both Contorno and Calderone (AC: I, 3); the latter also says that the Catania family dropped the practice of introducing new recruits after 1981 (AC: I, 18). — Diego Gambetta, The Sicilian Mafia The Business of…, 934