# Secondary Rules of Interpretation
## (1) Expressio Unius Est Exclusio Alterius
- Meaning: Express mention of one thing implies the exclusion of another.
- If two or more things belonging to a particular class are mentioned, other members of that class are silently excluded.
- Example: A statute refers to 'lands, houses and coal mines' → other mines (except coal mines) are excluded. They cannot be brought in under the general term 'lands'.
## (2) Noscitur a Sociis (Construction of Associated Words)
- Meaning: The meaning of a word is to be judged by the company it keeps.
- Words in a statute are construed with reference to words found in immediate connection with them.
- If two or more words capable of analogous meanings are grouped together, they should be understood in a cognate sense — they take their colour from each other.
Difference from Ejusdem Generis: Noscitur a Sociis applies to words of similar meaning grouped together; Ejusdem Generis specifically applies to general words following specific words.
## (3) Effect of Usage
Two Latin maxims govern this:
### (a) Contemporanea expositio est optima et fortissima in lege
- The best interpretation of a document is to read it as it would have been read when made.
- Old statutes/documents are interpreted as they would have been at the time of enactment.
- The interpretation is then exposed to new circumstances and technology.
### (b) Optima Legum interpres est consuetudo (Custom is the best interpreter of law)
- If there is a uniform, notorious practice continued under an old statute, and the legislature has not amended it, the usage/practice receives judicial or legislative approval.