International Standard Serial Number International Standard Serial Number An International Standard Serial Number (ISSN) is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title. ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization (ISO) international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard. When a serial with the same content is published in more than one media
Standard Open Standard Open Second Open or Standard Open (coded SO) is a British coach designation for open-plan second class (later standard class) coaches with 2+1 abreast seating, usually seating 48 passengers. Second class coaches with more conventional 2+2 abreast seating were designated Tourist Standard Open (TSO). There were a number of variations. The majority (95) were built using the same body shell as the Mark 1 SK and TSO. When production started, these were classified as Third class. There were also 15 "true" Second class coaches, also known as "Boat Seconds" as they were used on Boat trains (which were still