In Part 1, the firefighter's handbook contains an ironically incorrect allusion to early American history.
Stoneman and Black drew forth their rule books, which also contained brief histories of the Firemen of America, and laid them out where Montag, though long familiar with them, might read: Established, 1790, to burn English-influenced books in the Colonies. First Fireman: Benjamin Franklin.
Readers likely know this is all false, especially American readers, who should be familiar with the unique free speech protections in the First Amendment that directly contradict the censorship in Fahrenheit 451. There is special irony in the reference to Benjamin Franklin, who was in fact a newspaper printer, a writer, a proponent of free speech, and someone who valued knowledge and debate. It is true, however, that Franklin founded Philadelphia's first fire department, along with a library and a college that is now known as the University of Pennsylvania. It's hard to think of a historical figure who would have been more opposed to the sort of censorship the firemen are undertaking!
The ironically false framing of these allusions also subtly indicates what happens in a censored society. When only certain viewpoints or claims can be circulated, discovering the truth, or even simply differing perspectives, can be difficult or impossible, and it will begin to seem as if the world has always been, and must always be, the way it is right now.