Thornfield Real Estate Lawyer, Missouri, page 4

A fee charged by real estate brokers and apartment-finding services in exchange for locating a rental property. These fees are permitted by law. Some landlords, however, charge finder's fees merely for renting a place. This type of charge is not legitimate and, in some areas, is specifically declared illegal.

A nonrefundable fee charged by a landlord when a tenant moves in. The fee covers the cost of cleaning the rented premises after you move out, even if you leave the place spotless. Cleaning fees are illegal in some states and specifically allowed in others, but most state laws are silent on the issue. Landlords in every state are allowed to use the security deposit to clean a unit that is truly dirty.

A payment required by a landlord to ensure that a tenant pays rent on time and keeps the rental unit in good condition. If the tenant damages the property or leaves owing rent, the landlord can use the security deposit to cover what the tenant owes.

A promise that pledges nothing, because it is vague or because the promisor can choose whether or not to honor it. Such promises are not legally binding. For example, if you get a new job and promise to work for three years, unless you resign sooner, you haven't made a valid contract and can resign or be fired at any time.

A valid contract in which a copyright owner authorizes another person or entity (called the licensee) to exclusively exercise one or more of the rights (or portion of such rights) that belong to the copyright owner under the copyright. The licensee is said to 'own' the rights granted in the license and is referred to as a copyright owner.

Principles of international law so fundamental that no nation may ignore them or attempt to contract out of them through treaties. For example, genocide and participating in a slave trade are thought to be jus cogens.