Coe talker is a term used to describe people who talk using a coded language. It is frequently used to describe Native Americans who served in the United States Marine Corps whose primary job was the transmission of secret tactical messages. Code talkers transmitted these messages over military telephone or radio communications nets using formal or informally developed codes built upon their native languages. Their service was very valuable since codes and ciphers can be broken, but languages must be studied for a long time before being understood.