Opinion | Trump said, ‘Read the books! Read the manuals!’ Here is what they contain. - The Washington Post

Located in a secret alcove in the White House is a set of manuals. They explain in simple language and with illustrations every matter the president might encounter. Everyone knows about them, so that you can allude to them in conversation and people know what you are talking about: The Manuals, The Books. You might as well say “the Constitution” for how recognizable these are to the average listener. (Although the interviewer in this situation does not understand the reference, this is because he is from Australia; everyone in America knows about the presidential Manuals, Books.) But only the president has access to the wisdom they contain, which is why his decisions are always so opaque and baffling to all those around him. ....
https://www.washingtonpost.com/opinions/2020/08/06/trump-said-read-books-read-manuals-here-is-what-they-contain/