What are "substantiating documents" in relation to Marine Corps correspondence?

Substantiating documents refer to materials that provide supporting evidence or additional information relevant to a specific piece of correspondence. In the context of Marine Corps correspondence, these documents might include data, references, or any other materials that clarify, justify, or elaborate on the points made in the correspondence.

Such documents are essential because they lend credibility and context to the communication, ensuring that decisions and actions taken based on the correspondence are well-informed and backed by the necessary facts. This makes them an integral part of the correspondence process, as they enhance the understanding and validation of the issues being addressed. By providing this context, substantiating documents assist in maintaining transparency and accountability within the correspondence system.