The terms special edition, limited edition, and variants such as deluxe edition, or collector's edition, are used as a marketing incentive for various kinds of products, originally published products related to the arts, such as books, prints, recorded music and films, and videogames, but now including clothing, cars, fine wine, and whisky, among other products. A limited edition is restricted in the number of copies produced, although in fact the number may be very low or very high. Suzuki (2008) defines limited edition products as those “sold in a state that makes them difficult to obtain because of companies limiting their availability to a certain period, quantity, region, or channel". A special edition implies there is extra material of some kind included. The term is frequently used on DVD film releases, often when the so-called "special" edition is actually the only version released. Collector's edition Collector's edition may just be another term for special edition and limited edition products that include additional features or items that regular versions do not have. When referring to books, collector's edition products may refer to books in special limited and numbered editions, sometimes hand-bound, and signed by the artist and containing one or more original works or prints produced directly from their work and printed under their supervision. Whatever these extra features or items are, they must represent additional value to collectors of these products. Hand Finishing Many collector's editions include hand finished elements to further enhance the finished product above and beyond what a machine could create. Tipped In Pages For elements such as signatures and autographs or tipped-in plates for illustrations, tipped in pages are pages of the book that are printed separately from the main body of the book, but then attached to it. Onlays Onlays are materials that adhere directly to the overall binding material of the book and are another key feature of many special editions. Disc products Popular culture widely employs Special, Deluxe, Expanded and Limited Edition in marketing, releasing subsequent, improved versions of film DVDs, music, and video games. Companies widely use special editions and incremental improvements to sell the same products to consumers multiple times. This has been seen in the 10th Anniversary edition of Titanic, which simply consists of the first two discs of the previous Special Collector's edition, only with new packaging, and on CD with the 30 Year Anniversary Edition of Bob Marley's