The names assigned to the ceramic types are arbitrary. In United States, the common practice is a two-part name, the first part being an arbitrary geographic reference and the second part providing a brief description of the pottery's most obvious design attributes. Thus, for example, the type "Flagstaff Black-on-white" was first defined using a collection from the vicinity of Flagstaff, Arizona, and its primary design attribute is the use of black paint on a white background.