This part of IEC 62818, which is a Technical Specification, establishes a system of fiber reinforced composite cores used as supporting member material in conductors for overhead lines which may be used as the basis for specifications. This document is applicable to fiber reinforced composite core, with a metallic matrix, used as supporting member material in conductors for overhead lines. This document gives guidance on: defining the common terms used for fiber reinforced composite cores with a metallic matrix, prescribing common methods and recommendations to characterize the properties of fiber reinforced composite cores based on single or multi-wires, with MMC (Metallic Matrix Composite) used as a supporting member material in conductors, prescribing or recommending acceptance or failure criteria when applicable. These tests, criteria and recommendations are intended to ensure a satisfactory use and quality under normal operating and environmental conditions. This document does not prescribe performance or compliance criteria which may be required but indicative values could be given in Annexes for guidance.