recommendatory [ˌrekə'mendəˌtoʊrɪ]

例句:

• The recommendatory principle and method by the authors are also adapted to high speed train.
  作者提出的列车质量计算的原则和方法也适用于高速列车.
  
• National standards and trade standards are divided into compulsory standards and recommendatory standards.
  国家标准、行业标准分为强制性标准和推荐性标准.