Pictographs in the Nahuan language on a page from the Codex Borgia, a rare manuscript from pre-Columbian Mexico, dating from the fifteenth or early sixteenth century.

In the letter, Lopez Obrador requests the Vatican return the Codex Borgia, two other ancient codices as well as its maps of the Aztec capital of Tenochtitlan for a one-year loan in 2021.