The 503rd Infantry Regiment and the 2nd Infantry Division are both formations of what military branch
2nd Infantry Division (United States) The 2nd Infantry Division ("Indianhead"; "2ID," "2nd ID", or "Second D") is a formation of the United States Army. Its current primary mission is the defense of South Korea in the initial stages of an invasion from North Korea until other American units can arrive. There are approximately 17,000 soldiers in the 2nd Infantry Division, with 10,000 of them stationed in South Korea, accounting for about 35% of the United States Forces Korea personnel.
2nd Legions Home Army Infantry Division The 2nd Legions Home Army Infantry Division “Pogon” (Polish: 2 Dywizja Piechoty Legionow AK "Pogon", 2 DP Leg. AK) was a unit of the Polish Home Army (AK), created in 1944 in the Home Army District Radom - Kielce. Creation of the division was based on a September 1942 order of the AK headquarters, which stated that in the future Operation Tempest, the Home Army units were to be named after pre-September 1939 units of the Polish Army. Therefore, the Second Legions Home Army Infantry Division was based on and named after the 2nd Legions Infantry Division, which until the Invasion of Poland had its headquarters in Kielce.