The Stanard Catalog of World Coins is a series of numismatic catalogs commonly known as the Krause catalogs in the numismatic hobby. These massive by-century volumes list by date virtually every coin type, most photographed, with mintage and other information, plus market valuations in 4 to 5 grades. Listings are by denomination rather than series, as in earlier world coin catalogs. The proprietary KM (or K) numbers are widely used; for some countries specialized or earlier systems such as Y (Yeoman) and C (Craig) are given instead. The century format is inconvenient and expensive for many who collect geographically, and date listings are clipped at the century mark. Originally covering 1800-date, the main catalog (first edition 1972) evolved into an annual 20th century-only work, plus separate 17th, 18th, and 19th century volumes which are revised less frequently. Beginning with the 34th (2007) ed, listings after 2000 are dropped, and a 21st Century catalog covers 2001-date. Data from the by-century volumes are collated together in special editions for Crowns, Gold, German, and North American coins. Fantasies and medallic issues, which do not appear in the other catalogs, are covered in Unusual World Coins. Starting with 2002 editions, the catalog numbers and other specifications previously shown in bold or larger text were buried in small type to create space for inclusion of additional information such as main design elements and designer names. Since then, readability has gradually improved, but pre-2002 editions are still clearer in some ways. Notable editions: 12th (1986) &19th (1992) are two-volume hardcovers covering 1700-date; 13th (1987) is the last edition to include cross-references to Yeoman and Craig; 23rd (1996) is the last main edition covering 1800-date; 33rd (2006) is the last 20th century edition including 21st century listings. List priced at $55 to $70 they are often discounted, and can be found iin many public libraries. Older editions are steeply discounted even though revisions between editions in many areas are minimal. Pirated DVD versions are sold on eBay, and an official DVD version of the 19th, 20th, and 21st C. eds. was introduced August 2007. A distant second in terms of collector use is Whitman Publishing's A Catalog of Modern World Coins 1850-1964 by Richard S. Yeoman, now in its 14th (2008) edition, and source of the "Y" numbers. The companion Coins of the World 1758 - 1850 by William D. Craig was last printed in a 3rd edition in 1976. Early editions attribute authorship to Chester L. Krause (krou as in plow -zee), the publisher, and Clifford Mishler, although Colin R.Bruce II was the actual chief compiler and is given as editor or senior editor on later editions. Cotributions from many collector experts and dealers are collated by the KP staff to create revised listings and valuations for new editions. Valuations may or may not reflect the market accurately, and collectors should use the Krause values as a starting point for their own market research.