The Air Force doesn’t know who is going to build the KC-X tanker, but the service has decided what to call the jet.

Drum roll, please. The KC-X is designated KC-45A.

While the service didn’t make a formal announcement about the KC-45A naming, the designation has started to appear in briefings given by Air Force officials and a service spokesman confirmed the name.

Technically, KC-45A is the tanker’s mission design series name. The “KC” designates the jet as a tanker. Why “45A” was chosen isn’t clear, other than it doesn’t seem to conflict with any other cargo or tanker aircraft.

The name also avoids appearing to side with either of the jets vying for the production contract. Boeing Co. calls its proposed Air Force tanker the KC-767 while Northrop Grumman calls its candidate the KC-30.

The nickname for the jet is still to be decided.