"A reference letter or letter of reference is a letter in which the writer makes a general assessment of the qualities, characteristics, and capabilities of a person, or confirms details about that individual's situation or circumstances. Reference letters are different from recommendation letters in the sense that they are usually more general in nature and are not normally addressed to a specific requestor. Normally, letters of reference are addressed as; "To Whom It May Concern" or "Dear Sir/Madam". Letters of reference typically include: character-related, college program admission-related, employment-related, or general purpose letters."
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