"Separate" airline should hold their own "separate" AOC, but no one (
AFAIK) didn't went so far, just too expensive. $)
Back to the topic - it has more on ads side rather than ops or pax issues (yes, actually cargo division in many cases is financially independant from main airline pax ops, so they need to pay themselves to become better known and "always in sight").
For example there is now LH MD11F painted in "WOW" c/s, which is purely advertisement, becuase freight forwarders never see aircraft and pax around have no clue what "WOW" stands for. But this particular airframe photos are extensively used when WOW members advetising their combined serices, and computer-made virtual photo sounds too cheap
