This is a Latin maxim used as one of the rules of Interpretation of Statutes. The maxim means that if one thing is expressly mentioned it implies that other things of the same type are excluded. Thus when a Statute expressly mentions one thing it creates a presumption that other things that are not mentioned are excluded.
When an Act expressly mentions things of a particular class then the other things of the same particular class not expressly mentioned are excluded from the Act. Thus, the express words of the Act must be generally applied unless the Act provides limiting the meaning of the words used in the Act.
If the legislature intends to include a particular thing within the ambit of the legislation passed by it then the legislature would have preferred to include it expressly. If the legislature does not include any particular thing then it can be inferred that it was deliberately excluded. Thus, when the exclusion of something is not expressed it is implied. Accordingly, when a law, contract, or a will specifies certain persons or things it implies the exclusion of all other persons and things.
However, this legal maxim has some drawbacks. It is said that the things or people not expressly mentioned in the legislation may be not mentioned accidentally or inadvertently. While drafting particular legislation the draftsman may not realize the people or the things not mentioned or excluded by him may actually require a specific mention in the legislation. Because of this if the application of the maxim results in injustice or inconsistency the maxim should not be applied. Thus, the universal application of the maxim is neither possible nor recommendable.
Bennett Coleman & Company v/s Union of India-
In this case, the fundamental rights given in Part 3 of the Constitution of India were in question. The fundamental rights provided by Articles 15, 16, and 19 as per the Constitution are given only to the citizens of India. The non-citizens are expressly excluded from claiming these fundamental rights as they are only available to the citizens. In this case, the Supreme Court held that rights guaranteed by Article 19 are exclusively given only to the citizens thus all non-citizens or legal persons cannot claim these rights. However, it must be noted that citizens can claim these fundamental rights through legal persons as the ultimate beneficiary of these rights will be the citizens and not the legal persons.