All sorts of men who wear uniforms are men in uniform.
A uniform is an outfit worn by people in a particular profession that identifies them as member of that profession. It can also be an outfit that identifies all the members of a particular team or group. Many men and women are attracted to men in uniform, some because of the way men in uniform look and others because of what the uniform stands for. This is a uniform fetish. Men in uniform is also a colloquial term that refers to men in the military such as army, navy, airforce men and marines. It can also apply to firemen, police, pilots, baseball players and any man who wears a uniform.
Many men in uniform are identified as heroic and masculine. The military, cops and firemen and athletes commonly wear uniforms and are all considered extremely sexually attractive by large groups of gay men. Some men and women enjoy sex with a man wearing a uniform and there are some adult websites showing military men or athletes masturbating or having gay sex.