Sophisticated methods have been developed for checking whether voters stood by their declared intentions. Until the referendum of June 9, 1991, abolished this system, Italian voters could express up to four preferences among the candidates on any party slate. These votes could be cast by writing in either the candidate's name or the corresponding number, since numbers are easier to memorize. Thus, voters wishing to sell their vote were instructed to select particular numbers and list them in a particular sequence. Checking the constituency list against the key sequence made accurate identification possible. Votes were usually sold in blocks by middlemen known as capibastone.

XREF: Relates to electoral integrity literature and how secret-ballot systems historically failed to prevent corruption.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 983