An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is especially helpful in distinguishing between serials with the same title. ISSN is a worldwide identification code used by publishers, suppliers, libraries, information services, bar coding systems, union catalogues, etc. for citation and retrieval of serials such as Journals, Newspapers, Newsletters, Directories, Yearbooks, Annual Reports, Monograph series, etc. The benefits of having ISSN include international publicity and recognition of serials by automatic inclusion in the International Serials Directory Database.