The definition of a unique object according to Wikipedia is "the uniqueness of an object such as a document, painting or photography." It emphasizes the "specificity and the increased value of the individual piece of art." Wikipedia has some problems with the explanation of the word "Edition" (at least in the German version). The term "unikatär" (which describes a kind of hybrid between a unique piece of art and an edition) is completely ignored by Wikimedia, although it relates more and more to the language and practice of the art scene and the art trade. Dieter Roth and Gerhard Richter, for example, have often intervened manually in the production of their graphic editions or multiples - thus creating unique works of art, quasi editions with unique character. For all variants of editions the rule is: the smaller the edition the more rare and usually the more valuable is the work.