A Common Land Unit (CLU) is the smallest unit of land that has a permanent, contiguous boundary, a common land cover and land management, a common owner and a common producer in agricultural land associated with USDA farm programs. CLU boundaries are delineated from relatively permanent features such as fence lines, roads, and/or waterways.
Sometimes an object which comprises a CLU may be repaired with wire. 
A CLU is sometimes delineated by a fence line so that sometimes an object which comprises a CLU  - namely a fence - may be repaired with wire.