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
Opposite Track Path Opposite Track Path Opposite Track Path (OTP) is a technique used in optical technology, which when correctly implemented allows faster (though not un-noticeable) switching from layer 0 to layer 1. A dual-layer DVD or Blu-ray disc with Opposite Track Path means that layer 0 is written in a spiral track starting at the inside of the disc reading outwards, whereas the layer 1 spiral starts at the outside of the disc reading inwards. Both tracks are written so that the DVD player will rotate the disc in the same direction. Unlike DVD-ROM discs, DVD video discs are mastered such that