In simple terms, to codify something means to enshrine a right or a rule into a formal systematic code. It could be done through an act of Congress in the form of a federal law. Similarly, state legislatures can codify rights by enacting laws. To codify Roe for all Americans, Congress would need to pass a law that would provide the same protections that Roe did – so a law that says women have a right to abortion without excessive government restrictions. It would be binding for all states.