2. 需求规范 (Specification of Requirements)
本文中的关键词 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 和 "OPTIONAL" 应按 RFC 2119 [RFC2119] 中的描述解释.
本文中的关键词 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 和 "OPTIONAL" 应按 RFC 2119 [RFC2119] 中的描述解释.