From the Purpose: "U.S. Citizenship and Immigration Services (USCIS) is issuing policy guidance in the USCIS Policy Manual [hyperlink] to provide clarifications regarding certain naturalization applications filed by veterans of the U.S. armed forces under section 329 of the Immigration and Nationality Act (INA). These clarifications ensure eligible military veterans who served honorably during specifically designated periods of hostility and meet all other statutory requirements for naturalization are able to naturalize and become U.S. citizens in accordance with U.S. immigration laws."
USCIS PA-2021-09; U.S. Citizenship and Immigration Services Policy Alert-2021-09
U.S. Citizenship and Immigration Services: https://www.uscis.gov/