Warrant officers hold warrants from their service secretary and are specialists and experts in certain military technologies or capabilities. The lowest ranking warrant officers serve under a warrant, but they receive commissions from the president upon promotion to chief warrant officer 2. These commissioned warrant officers are direct representatives of the president of the United States. They derive their authority from the same source as commissioned officers but remain specialists, in contrast to commissioned officers, who are generalists. There are no longer any warrant officers in the Air Force.

NOTE: Naval officers wear distinctively different rank devices depending upon the uniform they're wearing. The three basic uniforms and rank devices used are: khakis, collar insignia pins; whites, stripes on shoulder boards; and blues, stripes sewn on the lower coat sleeves.