The landlord and tenant may agree on additional terms such as changes to the unit prior to the tenant`s move in or rules regarding the use of common areas or amenities. Additional terms must not be contrary to the Residential Tenancies Act or the Ontario Human Rights Code. Among the frequently used unenforceable rental conditions are: prohibition of pets, prohibition of roommates or customers, or additional charges such as bonds or interest. Landlords may require tenants to have liability insurance covering unintentional or accidental damage to the unit or persons within the unit, as well as any legal costs incurred as a result of such damage. Tenant insurance is intended to protect a tenant`s property in the event of accidental damage. The contract must be signed by the landlord and tenant. .