The USDA uses %DV for nutrition labels which is an incomplete nutrient list*. RDA is an older but more complete list. We have to use %DV for the nutrition labels to make it easy to copy a nutrition label into FitDay but those labels do not go into the level of detail that RDA does with macronutrients.
* At the time FitDay was first developed. This may no longer be true. I'd have to do some research as I do not know enough about this myself.