[This version of the document is a draft version for an RFC6044bis that will describe the mapping between the Diversion header defined in RFC5806 and the new History-Info header defined in RFC7044.] Although the SIP History-Info header is the solution adopted in IETF, the non-standard Diversion header is nevertheless already implemented and used for conveying call diversion related information in the Session Initiation Protocol (SIP) signaling. This document describes a recommended interworking guideline between the Diversion header and the History-Info header to handle call diversion information. In addition, an interworking policy is proposed to manage the headers' coexistence. The non-standard Diversion header is described, as Historic, in [RFC5806]. The History-Info header is described in [RFC7044] that obsoletes [RFC4244] initially describing the History-Info header. [RFC7044] defines an optional SIP header field, History-Info, for capturing the history information in requests and SIP header field parameters for the History-Info and Contact header fields to tag the method by which the target of a request is determined. RFC7044 also defines a value for the Privacy header field that directs the anonymization of values in the History-Info header field. Since the Diversion header is used in existing network implementations for the transport of call diversion information, its interworking with the SIP History-Info standardized solution is needed. This work is intended to enable the migration from non- standard implementations and deployment toward IETF specification- based implementations and deployment. This document obsoletes [RFC6044].