International Securities Identification Number (ISIN) is a securities coding standard developed by International Standard Organization (ISO), and it published in "Securities and related financial instruments — International securities identification numbering system"(ISO6166). The standard covers stocks, bonds, futures, options, warrants and other financial instruments. Currently, ISO6166 is well recognized by many international organizations of securities industry, such as G30, CPSS, IOSCO, and ISSA. ISIN consists of a total of 12 characters as follows: 1) A Prefix using the alpha-2 country code specified in ISO 3166;2) The basic number, which is nine characters (alphanumeric) in length. Where the existing national number consists of nine characters, this number may be used; where the existing national number consists of fewer than nine characters, this also may be used, but zeros shall be inserted in front of the national number. Where a national check digit exists, it shall be regarded as part of the basic number within the nine characters;3) A check digit in the end. Association of National Numbering Agencies (ANNA) serves as the Registration Authority for ISIN numbering standards. It details organizations, known as National Numbering Agencies (NNA's) that are responsible for issuing the ISIN in each country.