Campaign Code (utm_id) for assisted conversions
In our system we use utm_id (known as Campaign Code in Analytics web interface) to store information about ad (generic one, not necessarily AdWords ad) that led user to destination website.
I'm able to get the values for Campaign Code in both web interface and reporting API, but only for direct conversions. When listing assisted conversions metrics (prefixed with "mcf:"), utm_id is not available. That's a little weird, because other utm parameters are present, just the utm_id is missing. I checked web interface, API and its docs, but I haven't found any clues.
Is there a reason for not including utm_id in MCF API? Is there any way to get the data?