Final answer:
The spacing of ribbons on a service uniform varies slightly by military branch, but commonly there is no space between rows or ribbons with specific positioning above the left breast pocket.
Step-by-step explanation:
The question regarding the spacing between ribbons on a service uniform relates to specific military dress regulations. Although the exact spacing can vary slightly depending on the branch of the military, generally, ribbons are to be worn with no space between rows and aligned in rows that cover the ribbons below. For branches such as the United States Army, ribbons should be positioned 1/8 inch above the left breast pocket and spaced with no space between ribbons or rows of ribbons. In contrast, the United States Marine Corps specifies that ribbons should be worn with a 1/8 inch space between rows. It's important for service members to consult their specific service's uniform regulation manual for precise guidelines.