The Wisconsin Department of Agriculture Trade and Consumer Protection has adopted Wisconsin Administrative Code rules applicable to the conduct of landlords in residential rental practices.  A rental agreement is defined in Wis. Admin. Code ATCP 134.02(10) as “an oral or written agreement for the rental or lease of a specific dwelling unit or premises, in which the landlord and tenant agree on essential terms of tenancy such as rent”.  Rental agreements can generally be divided into two main categories:  (1) leases – those agreements where property is rented for a definite period of time, and (2) informal tenancies-those agreements with no definite termination date, including periodic tenancies and tenancies at will.  Use of written leases or rental agreements minimizes disagreements and disputes.  Counties and local municipalities may also have landlord-tenant ordinances.