P-Charge-Info: A Private Header Field (P-Header) Extension to the Session Initiation Protocol (SIP)
draft-york-p-charge-info-08

This one's been in progress for 16 years? Oh, wow ...

Is "private network" the right term to use in 

  If an untrusted entity were inserted between the trusted entities, it
   could potentially interfere with the billing records for the call.
   If the SIP connections are not made over a private network, a
   mechanism for securing the confidentiality and integrity of the SIP
   connection MUST be used to protect the information.  One such
   mechanism could be TLS-encryption of the SIP signaling stream.

? I'm not sure what the attributes are that you're expecting. Even a reference to a definition of "private network" would be helpful.

Is 

A.1.  P-Charging-Vector

   P-Charging-Vector is defined in Section 4.6 of [RFC7315] and used by
   the 3GPP to carry information related to the charging of a session.
   There are, however, some differences in the semantics associated with
   P-Charging-Vector and P-Charge-Info.  P-Charging-Vector is mainly
   used to carry information for correlation of multiple charging
   records generated for a single session.  On the other hand, P-Charge-
   Info is used to convey information about the party to be billed for a
   call.  Furthermore, P-Charging-Vector has a mandatory icid-value
   parameter that is a globally unique value to identify the session for
   which the charging information is generated.  Such a globally-unique
   identifier is not necessary when carrying information about the user
   to be billed when it is attached to the corresponding session-related
   signaling.

a privacy concern?

Are the Alternatives in Appendix A mutually exclusive from P-Charge-Info? Is it an error if multiple of these are present in a single SIP request? If that's not an error, which alternative has priority, or is that not deterministic?