Under what conditions are additional 4"x6" stickers acceptable?

Additional 4"x6" stickers are acceptable specifically for military requirements. This is due to the unique nature of military vehicles and their operational needs, which may necessitate additional identification or information that is not typically required for civilian vehicles. Military personnel often have specific regulations and needs that justify the use of extra stickers for identification, communication of special instructions, or marking purposes. This ensures that military vehicles are clearly identified and can operate effectively under various conditions, including those that differ from civilian standards.

In contrast, the other conditions listed may not universally justify the inclusion of additional stickers in general vehicle operations. For example, while not obstructing the view is important for any vehicle, it does not alone warrant the installation of extra stickers. Similarly, commercial vehicles have their own regulations, but these typically adhere to standard formats and practices that do not include additional stickers unless specifically authorized. Police approval can also vary case by case, and it wouldn't represent a broad acceptance criterion for all vehicles. Thus, the stipulation related to military requirements stands out as the correct context for allowing additional stickers.