/ˌʌnəˈfɪʃəl ˌmɛməˈrændəm/ – Phrase
Definition: giác thư không chính thức, bị vong lục không chính thức.
A more thorough explanation: An unofficial memorandum refers to a written communication or document that is not formally recognized or authorized by an organization or entity. It is not an official or formal record and may not carry the same weight or authority as an official memorandum or communication.
Example: The attorney prepared an unofficial memorandum outlining the potential legal issues for the client’s case.