unwritten

unwritten
adjective
  1. not recorded in writing
    未写下的;无文字记录的
    documenting unwritten languages.
    记录无文字语言。
    ■(especially of a law) resting originally on custom or judicial decision rather than on statute
    (尤指法律)未成文的
    an unwritten constitution.
    未成文宪法。
    ■(of a convention) understood and accepted by everyone, although not formally established
    惯例的,因袭的
    the unwritten rules of social life.
    社会生活中的不成文规定。
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