Quick Summary:

The draft proposes new Call-Info Header fields to label the type/nature of the call.

Overall the draft appears to be well written. There are some nits as defined in the GenArt.  In addition to those nits, the below text in IANA section seems incorrect and the order should be changed:

    +--------------+----------------+-------------------+------------+
    | Header Field | Parameter Name | Predefined Values | Reference  |
    +--------------+----------------+-------------------+------------+
    | [this RFC]   | Call-Info      | confidence        | No         |

I don't have any other concerns or comments in terms of the operational aspects of this draft.

Thanks,
Nagendra