The Vichy Memorandems were a series of Nazi communications regarding the Nazi search for the Hand of God.
The Nazis sent the Vichy Memorandems regarding the Ahnenerbe obtaining a Hand of God, a weapon believed to be strong enough to allow the Nazis to win World War II. The Memorandems describe how the Hand of God was stolen en route to Berlin by Delphine Seydoux who the Nazis eventually determined was a Woman of Letters instead of French Resistance as was originally believed.
After World War II, the Vichy Memorandems would go on to confuse historians who could never figure out what they were talking about. They ultimately ended up in history books about the Ahnenerbe and the Nazis.
In 2016, while looking for a way to defeat the Darkness, hunter Sam Winchester started looking through history instead of lore for anything useful. Sam found the Vichy Memorandems and was able to piece together their significance with the help of information stored in the Men of Letters bunker.