Sylloge. A catalog of a collection; a compiled listing of related numismatic items. Such a compendium usually illustrates each item although the amount of cataloged detail is up to the compiler or cataloger. Often more descriptive information will help differentiate one variety from another. Elaborate sylloges are found in numismatics, published to help advance numismatic science. The word comes from syllogism, a logical or systematic scheme or formal arrangement; the application to the arrangement of numismatic items is obvious (and one of the first steps of cataloging).