Final answer:
The placement and arrangement of full-size decorations and service medals on a military uniform is regulated and typically involves wearing them on the left chest in order of precedence.
Step-by-step explanation:
The placement and arrangement of full-size decorations and service medals on a military uniform is a matter of formal regulation, which can differ by country and branch of service. These decorations are typically worn on the left chest area, above any ribbon bars. When multiple medals are to be worn, they are usually arranged in order of precedence, with the highest honor placed closest to the heart. It is important to consult specific military regulations to ensure proper display.