What was this corollary and addendum to and what was the purpose of it?

The corollary and addendum typically refer to supplementary statements that clarify or expand upon a primary principle or theory. In various contexts, such as legal documents or scientific theories, their purpose is to address exceptions, provide additional details, or specify conditions that enhance understanding of the main premise. By doing so, they ensure comprehensive application and interpretation of the original content while mitigating potential ambiguities.