unwritten law; common law
Legal term for law based on custom or precedent rather than written statutes. Contrasts with 成文律 (written law).
See also: 成文律
In England, unwritten law plays an important role.
unwritten rule; tacit understanding
Commonly used for social norms, customs, or implicit agreements that are not formally written down.
職場には、残業は断らないという不文律がある。
There is an unwritten rule at the workplace that you don't refuse overtime.
There's an unwritten rule at this company that you don't refuse overtime.
The senior members have long abided by the unwritten rule.
The new employee broke the unwritten rule and gave their opinion directly to the boss.
In this industry, not disclosing prices has become an unwritten rule.