A functionally classifie barn is a barn whose style is best classified by its function. Barns which do not fall into one of the broader categories of barn styles, such as English barns or crib barns, can best be classified by some combination of two factors, region and usage. Examples of barns classified by function occur worldwide and include, apple barn, rice barn, potato barn, hop barn, tobacco barn, cattle barn (pole barn), and the tractor barn. In addition, some barns incorporate their region into their style classification, examples would include the Wisconsin dairy barn, Pennsylvania bank barn or the Midwest feeder barn.