Diplomatic Correspondence and Secret Agreements

Letters, telegrams and undisclosed or narrowly negotiated diplomatic instruments, distinct from a publicly ratified treaty or declaration. Belongs here: the Amarna Letters as the earliest known corpus of diplomatic correspondence, the Molotov-Ribbentrop Pact for its secret protocol dividing Eastern Europe, the Sykes-Picot Agreement as an undisclosed wartime partition arrangement, the Yalta Agreement as a great-power summit understanding rather than a ratified public treaty, and the Zimmermann Telegram as an intercepted diplomatic communication. Does not belong here: a publicly negotiated and ratified treaty or pact, filed under one of the two treaty groups or under Modern International Agreements and Pacts as its own era requires.