High Quality Content by WIKIPEDIA articles! A functionally classified barn is a barn whose style is best classified by its function. Barns that 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 include the Wisconsin dairy barn, Pennsylvania bank barn, or the Midwest feeder barn.