This International Standard provides identification coding for manifolds used in hydraulic systems and for component installation features (for example, mounting surfaces or cavities) of such manifolds. It specifies identification codes to be marked on manifold blocks and correlated with product and service documentation such as circuit diagrams, bills of material and assembly drawings, for the purpose of facilitating assembly, installation, use and service of systems in which the manifolds are applied. The codes define a unique identifier traceable to associated documentation for each mounting surface or cavity. The installed component may be marked or tagged with the same identifier when such marking is necessary for clarity in assembly or service