I was on a flight from Kadena AB to Elmendorf AFB with 54 human remains from Vietnam. I still remember the number because it was 9 pallets with 6 remains on each pallet.
We had just one passenger, a Marine 2nd LT. About half-way through the flight I went down to the cargo compartment and invited him up to the flight deck since it would be a little more pleasant for him to ride up there rather than being alone with the human remains in the cargo compartment.
He turned down the offer and said he preferred to remain in the cargo compartment. I asked why.
The young Marine said he was returning to the states on emergency leave because of the death of his brother, a 2Lt Army helicopter pilot who had been killed in action. He had looked at the names on the transfer cases and found his brother's name ... until that time he he had not known that he would be on the same C-141 on which his brother's remains would returned to the states.
I went back up to the flight deck and informed the aircraft commander about this situation. He called ahead to Elmendorf and told them what we had discovered and we then declared our single passenger was a BLUE BARK. MAC Manual 55-1 had a list of code names in the back. BLUE BARK is the code name for a relative or dependent that is traveling with a deceased member. If there is one staff car left in the motor pool, the BLUE BARK will get it before a general does. The Marine was able to escort his brother all the way home.
This is one event in my 24 years in the Air Force I will always remember and it still brings tears to my eyes when I tell this story.
NOTE: "BLUE BARK", according to the Department of Defense dictionary: "U.S. military personnel, U.S. citizen civilian employees of the [DoD], and the dependents of both categories who travel in connection with the death of an immediate family member. It also applies to designated escorts for [said] dependents. Furthermore, the term is used to designate the personal property shipment of a deceased member." I searched for the origin of the term to see if there is any significance to it, but at this point, it appears to just be an arbitrary military code name and nothing more.
Or this: The word "blue bark" is an old Navy term, from the days of the Ships-of-the-line. War ships could be identified by a gold line the adorned the trim of the ship. When the captain of the ship, or another shipmate, died while in battle (and eventually just at sea), the gold line was painted blue to allow other ships and those waiting at the dock time to render honors.