An ISSN is a standardized international code which allows the identification of a serial publication. An ISSN consists of eight digits in two groups of four, separated by a hyphen. You can enter an ISSN with or without a hyphen or leading zeros as shown below: FAST is a controlled vocabulary based on the Library of Congress Subject Headings (LCSH). FAST headings are categorized into seven subject facets and one form/genre facet: Topic, Place, Time, Event, Person, Corporate body, Title of work, and Form/Genre. FAST headings provide additional subject information about a work and enable you to search the Classify database by subject. OCLC is a non-profit library cooperative, made up of thousands of member libraries throughout the world. OCLC does not sell books and the actual content is not provided in our database. Libraries add bibliographic records to WorldCat representing books and other items in their collections. The Classify prototype helps librarians apply classification numbers to resources in library collections. Only the metadata/citation is presented in Classify and WorldCat. Your local library may be able to help you gain access to a resource found through Classify and WorldCat. Classification schemes are used to provide a systematic arrangement of materials. The classification numbers applied to books and other materials are used to arrange items on shelves and to support browsing, filtering and retrieval of bibliographic information in online systems. The Classify prototype is designed to help users apply classification numbers. Classify provides a user interface and a machine service for assigning classification numbers and subject headings. The database is searchable by many of the standard numbers associated with books, magazines, journals, and music and video recordings. These numbers include: Source.