Branch optical cables, also known as distribution optical cables, are used to distribute fiber optic signals from a main cable to individual devices or endpoints. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube. This article explains eight of the most important global fiber and cable standards — ITU-T, IEC, TIA, ISO/IEC, and Telcordia — covering their scope, applications, and why they matter in real-world deployments. Fiber optic networks rely on a foundation of rigorous international standards that define. The manual is intended as a guide for technologists, middle-level management, as well as regulators, to assist in the practical installation of optical fibre-based systems.