Armband

They may be worn for pure ornamentation, or to mark the wearer as belonging to group, or as insignia having a certain rank, status, office or role, or being in a particular state or condition.

The phrase to wear your heart on your sleeve, meaning to show your feelings, to display an emotional affiliation or conviction, is supposedly related to armbands.

[citation needed] Armbands are often used to hold a smartphone or a portable music player on a wearer's arm while doing activities such as lifting weights, running, etc.

President Franklin D. Roosevelt wore a black armband mourning the recent death of his mother at the time he signed the declaration of war against Japan in December 1941.

[5] The term was used by Prime Minister John Howard, whose perspective on Australian history strongly contrasted with what he called the black armband view.