Diver down flag. A diver down flag, or scuba flag, is a flag used on the water to indicate that there is a diver below. Two styles of flag are in use. Internationally, the code flag alfa/alpha, which is white and blue, is used to signal that the vessel has a diver down and other vessels should keep well clear at slow speed.
Familiarize yourself with some friendly network cables and take a closer look at common types of network media, including twisted-pair cable, coaxial cable, fiber-optic cable, and wireless.
More About Network Cabling. The most commonly used types of network cable are the twisted pair, coaxial, Ethernet cross over, and fiber optic. The unshielded twisted pair (UTP) cable is used in many Ethernet networks. It has four pairs of wires that are housed inside of the lining of the cable.