ISO 3166-2:SM is the entry for San Marino in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions (e.g., provinces or states) of all countries coded in ISO 3166-1.
Currently for San Marino, ISO 3166-2 codes are defined for 9 municipalities.
Each code consists of two parts, separated by a hyphen. The first part is SM, the ISO 3166-1 alpha-2 code of San Marino. The second part is two digits (01–09).