A strangely worded question, but if I'm not misunderstanding you:
A "contract".
Memorandum of Agreement is a formal document that outlines an agreement between two entities. The MOA is typically written before the more detailed document.
Formal communication does not require the use of written reports to document all interactions. Formal communication may be in the form of either a verbal presentation of written documentation.
Papal Bull
written statement expressing intention of formal agreement
The Declaration of Independence.
report
report
report
report
Contract means to shrink. Or in the context of "a contract" :a legal document that states and explains a formal agreement between two different people or groups, or the agreement itself
A treaty is an agreement under international law between two or more sovereign states or international organizations. It's also known as an agreement, protocol, convention, or pact.
The introduction to a formal document is called a preamble.