1.1. 需求语言 (Requirements Language)
关键词 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" 和 "OPTIONAL" 仅在全部大写出现时, 按 BCP 14 [RFC2119] [RFC8174] 解释.
关键词 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" 和 "OPTIONAL" 仅在全部大写出现时, 按 BCP 14 [RFC2119] [RFC8174] 解释.