What is proper order of Vietnam era ribbons on class a army uniform?

The proper order of Vietnam era ribbons on a Class A Army uniform is based on the precedence of the awards. Generally, the order begins with the top row featuring the Medal of Honor, followed by the Distinguished Service Cross, Silver Star, and Bronze Star. Subsequent rows include the Purple Heart, Good Conduct Medal, and various campaign or service ribbons. It's important to refer to Army regulations for specific guidelines regarding placement and spacing.