초기에는 사법관계를 적용대상으로 하였으나, 오늘날 세법은 물론 행정법 등 공법관계를 포함한 거의 모든 법 분야에 있어 서 해석·적용의 기본원칙으로서 인정된다.
Initially, it was applied to judicial relations, but today it is recognized as a fundamental principle of interpretation and Application in almost all legal fields, including public law relations such as administrative law as well as tax law.