EXPRESSIO UNIUS EST EXCLUSIO ALTERIUS

Lat.: the expression of one thing is the exclusion of another. In construing statutes under this maxim, mention of one thing within the statute is said to imply the exclusion of another thing not mentioned. The maxim is an aid to construction and is applicable where the contrast between what is expressed and what is omitted enforces the inference that what is omitted must have been intended to have contrary treatment. Thus a statute granting certain rights to “police, fire, and sanitation employees” would be interpreted to exclude other public employees not enumerated in the legislation. Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016