question: What was the codename for the battle where the 9th Amphibian Tractor Battalion supported the 6th Marine Division?
answer: Operation Iceberg
context: Title: Scout and Sniper Company (6th Marine Division)
  Passage: The Scout and Sniper Company of 6th Marine Division was the division reconnaissance asset for the regimental commanders.  It was created from former Marine Raider Major Anthony "Cold Steel" Walker to form a scout company from Company H from out of one of the regiments of 6th Marine Division.  The Scout Company deactivated, along with 6th Marine Division, after the end of World War II.
  Title: 3rd Infantry Brigade, 2nd Infantry Division
  Passage: At the time of its activation, the 2nd Infantry Division was composed of the 3rd Infantry Brigade, which included the 9th Infantry Regiment; the 23rd Infantry Regiment and the 5th Machine Gun Battalion; the 4th Marine Brigade, which consisted of the 5th Marine Regiment, the 6th Marine Regiment and the 6th Machine Gun Battalion; 2nd Brigade of field artillery; and various supporting units.
  Title: 9th Marine Expeditionary Brigade (United States)
  Passage: The 9th Marine Expeditionary Brigade was a United States Marine Corps unit.  5th Tank Battalion, 5th Marine Division deployed with 9th MEB, later assigned to 1st Marine Division as a reinforcement Battalion.
  Title: 9th Amphibian Tractor Battalion
  Passage: The 9th Amphibian Tractor Battalion ("9th Amtrac Battalion") is an inactive amphibious assault battalion of the United States Marine Corps.  The battalion supported the 6th Marine Division during the Battle of Okinawa in World War II.
  Title: Battle of Okinawa
  Passage: The Battle of Okinawa (Japanese: 沖縄戦 , Hepburn: Okinawa-sen ) (Okinawan: 沖縄戦 , "Uchinaa ikusa " ), codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa by United States Marine and Army forces against the Imperial Japanese Army and included the largest amphibious assault in the Pacific War during World War II, the April 1, 1945, invasion of Okinawa itself.  The 82-day battle lasted from April 1 until June 22, 1945.  After a long campaign of island hopping, the Allies were planning to use Okinawa, a large island only 340 mi away from mainland Japan, as a base for air operations for the planned invasion of the Japanese home islands.
citations: 9th Amphibian Tractor Battalion Battle of Okinawa