[1] RFC 8006 - Content Delivery Network Interconnection (CDNI) Metadata (2016-12-14 14:55:04 +09:00) https://tools.ietf.org/html/rfc8006#section-4.1.4

[2] RFC 8006 - Content Delivery Network Interconnection (CDNI) Metadata (2016-12-14 14:55:04 +09:00) https://tools.ietf.org/html/rfc8006#section-4.2.6