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.
Digital audio cables (or, as they're often called, SPDIF cables) provide a handy way to route multi-channel audio from one device to another with minimal to no signal loss. The specs for a coaxial digital audio cable are the same as for a typical video cable: 75 ohm impedance, coaxial construction.