RFC 文档RFC 9878 - Updates to Private Header (P-Header) Extension Usage in Session Initiation Protocol (SIP) Requests and Responses4. IANA Considerations本页总览4. IANA Considerations 本页保留该章节的 RFC 文本, 并补充文档站点所需的导航元数据. RFC 文本 (RFC Text) 4. IANA ConsiderationsThis document has no IANA actions.