letter of intent

A letter of intent (LOI) is a document outlining the general plans of an agreement between two or more parties before a legal agreement is finalized.  

A letter of intent is not a contract and cannot be legally enforced; however, it signifies a serious commitment from one involved party to another. A LOI may be used to clarify a transaction before a full contract is drawn up, to officially declare a partnership or negotiation between two parties or to clarify a mutual understanding.

In the U.S, a LOI may also be known as a memorandum of understanding (MOU). 

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Student athletes often sign a national letter of intent to commit to a top college