There are two kinds of papers we keep see constantly in A Farewell to Arms.
This kind: I had his papers in my pocket and would write his family (30.67). – Identification documents, military documents, and the like.
And this kind: I went over there afternoons and afterwards stopped at a café and had a drink and read the papers (19.1). – Newspapers that report on the state of the war.
The first kind of papers relate to the identities of the people who possess them. If you have papers saying you are wounded and need to rest, then rest you will have. If you are out wandering around and you don’t have the papers to show you have permission to do so, you get arrested. Unless, like Frederic, you have a U.S. passport, and can row like crazy to neutral Switzerland. If, like Aymo in our example above, somebody else has your papers, you are probably dead. This is important to understanding how the identities of the characters (and of all of us) in the novel are defined and redefined, to themselves and others, by the papers they carry.
If you are searching for meta-fictional elements in A Farewell to Arms, look no further than the newspapers Frederic is constantly reading. As we discuss in the novel’s "Overview," while the historical events Frederic narrates were actually occurring, eighteen-year-old Ernest Hemingway was reading about them in the papers, and working as a fledgling journalist for…you guess it, a newspaper, the Kansas City Star. Frederic doesn’t do any writing that we can see in the novel, but when he reads the papers, he becomes a symbol of a part of Hemingway’s writing process.