Telephone numbers in Italy are managed by the Autorità per le Garanzie nelle Comunicazioni (AGCOM), a national regulatory authority for the communication industry located in Rome. Telephone numbers are defined by an open telephone numbering plan that assigns subscriber telephone numbers of six to eleven digits. In addition, other short codes are used for special services. The plan is organized by types of services, indicated by the first digit. Geographic landline numbers start with the digit 0, while mobile telephone numbers start with 3. Four types of emergency services use three-digit telephone numbers in the group 11X, including 112 for the Carabinieri. Other initial digits denote other services, such as toll-free numbers.