Everyone who joins the military has one thing in common, they must swear-in by repeating the enlisted or officer Oath. The Oath of enlistment is something that every service member must promise and adhere to for his/her entire military career. The Oath ceremony may be administered to a single applicant or a group. Friends and family members are invited to watch. And in some cases, thousands of NFL fans. Throughout the Salute to Service campaign each November, many NFL teams work with local military to host enlistment ceremonies and re-enlistment ceremonies on-field during pre-game or halftime festivities.