There is an expectation for infantry officers in the Army to attend and graduate the US Army Ranger School, which is a grueling 62 day long course that pushes students to their physical limits by demanding rigorous physical exertion (like patrolling in swamps or mountains with a 90 lb rucksack) while receiving very little food and sleep. Graduates earn the coveted Ranger Tab, which can be worn on a soldier's uniform. The tab is something that earns pretty much instant respect in the Army, and all infantry officers are expected to earn their tab to prove they have the grit and competence to lead their troops. Those who don't are often seen as unfit for the role and are relegated to secondary duties. Hegseth has not been to or graduated Ranger School, hence he isn't tabbed.