ZTE Corporation Traffic flows may be categorized and described using "Flow Specifications". RFC8955 defines the Flow Specification and describes how Flow Specification components are used to describe traffic flows. RFC8955 also defines how Flow Specifications may be distributed in BGP to allow specific traffic flows to be associated with routes. RFC 9168 specifies a set of extensions to PCEP to support the dissemination of Flow Specifications. This allows a PCE to indicate what traffic should be placed on each path that it is aware of. The extensions defined in this document extend the support for tunneled traffic filtering rules.