This family specification covers optical cables for telecommunication application to be used indoor. This specification does not cover cable assemblies, such as connectorized jumper cable, or the functional requirements for cable break-out (fan out). It also not covers cables for LAN applications and cables incorporating multimode fibres. Clause 5 of this standard describes a blank detail specification for optical telecommunication cables to be used for indoor cables. It incorporates some minimum requirements common to all European countries. Detail specifications may be prepared based on this family specification following in particular requirements of clause 5.