Final answer:
Only one 'V' device can be worn on any single military ribbon, representing valor. Additional awards are marked by other devices such as oak leaf clusters or stars.
Step-by-step explanation:
The question 'How many "V" devices can be worn on a ribbon?' pertains to United States military awards and decorations. In the context of U.S. military awards, a 'V' device is a bronze letter 'V' that denotes valor and is attached to certain medals and ribbons. According to military regulations, only one 'V' device may be worn on any single ribbon. If an individual is cited for valor on multiple occasions, additional awards are indicated by oak leaf clusters or service stars, depending on the military branch. However, the 'V' device itself is not cumulative—only one can be affixed to the ribbon to represent valor regardless of the number of citations.