This is the Rule that all organic certifiers, and likewise all organic producers, must follow. The following link offers an excellent way to electronically navigate this lengthy regulation:
Thinking about getting certified? Already certified, but you worry you don’t fully understand what is required? The NOP offers a variety of resources that present the regulation in plain language: NOP Training Modules and Guides
Want to dig deeper? Learn in detail about how the organic program is run from this handy navigational page from NOP: Welcome to the National Organic Program.