10. 规范性引用 (Normative References)

[RFC2119] Bradner, S., "用于在 RFC 中指示要求级别的关键词", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, https://www.rfc-editor.org/info/rfc2119.

[RFC6455] Fette, I. and A. Melnikov, "WebSocket 协议", RFC 6455, DOI 10.17487/RFC6455, December 2011, https://www.rfc-editor.org/info/rfc6455.

[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "超文本传输协议 (HTTP/1.1): 消息语法和路由", RFC 7230, DOI 10.17487/RFC7230, June 2014, https://www.rfc-editor.org/info/rfc7230.

[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "超文本传输协议版本 2 (HTTP/2)", RFC 7540, DOI 10.17487/RFC7540, May 2015, https://www.rfc-editor.org/info/rfc7540.

[RFC8174] Leiba, B., "RFC 2119 关键词中大写与小写的歧义", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, https://www.rfc-editor.org/info/rfc8174.