Unfortunately there is no sure remedy against lies. It is nor surprising, therefore, to learn that when mafiosi address one another, according to all the informants who have turned state's evidence, the rule is always to speak the truth. The mafioso can choose to remain silent; but if he elects to speak, he must not lie. Lying is supposedly punishable by expulsion and even death, although there is no record of such punishment's being carried out. The rule of truth is said to be even more important than the notorious rule of silence (VM: 77; TB: I, 126-127 and III, 110; TC: 21).

DEFINE: Clarifies that the Mafia's code of conduct centers on truth-telling among members, not just the better-known rule of omertà (silence).

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 319