/blæk ˈlɛtər lɔː/ – Phrase
Definition: Luật pháp cơ bản, rõ ràng và dễ hiểu.
A more thorough explanation: what the law actually says without consideration for its social, political and practical context; clear rules as established by law
Example: It is now black letter law that information generated and stored on computers and in other electronic forms is discoverable.