Fundamental Steps in Optimization Algorithms -- Fundamentals of Power System Protection -- Mathematical Modelling of Inverse-Time Overcurrent Relay Characteristics -- Upper Limit of Relay Operating Time -- Directional Overcurrent Relays and the Importance of Relay Coordination -- General Mechanism to Optimally Coordinate Directional Overcurrent Relays -- Optimal Coordination of inverse-time DOCRs with Unified TCCC -- Incorporating LP and Hybridizing It With Meta-Heuristic Algorithms -- Optimal Coordination of DOCRs With OCRs and Fuses -- Optimal Coordination with Considering Multiple Characteristic Curves -- Optimal Coordination with Considering the Best TCCC -- Considering the Actual Settings of Different Relay Technologies in the Same Network -- Considering Double Primary Relay Strategy -- Adaptive ORC Solver -- Multi-Objective Coordination -- Optimal Coordination of Distance and Overcurrent Relays -- Trending Topics and Existing Issues -- Appendix A: Some Important Data Used in Power System Protection -- Appendix B: How to Install PowerWorld Simulator (Education Version) -- Appendix C: Single-Machine Infinite Bus -- Appendix D: Linearizing Relay Operating Time Models -- Appendix E: Derivation of the First Order Thermal Differential Equation -- Appendix F: List of ORC Test Systems.