Provides product specifications for coated optical fibres with or without buffer and deals with two classes of optical fibres, class A (multimode) and class B (single mode). There are at present four categories of class A fibres and three of class B. Applies to: · optical fibres type A1a, A1b, A1c and A1d which are used or can be incorporated in information transmission equipment and optical fibre cables; · optical fibres category A2 which are used and can be incorporated in short links in communication equipment or in cables for short-distance links (typically up to 2 km); · optical fibres category A3 which are used or can be incorporated in short links in communication equipment or in cables for short-distance links (typically up to 100 m); · optical fibres class B which are used or can be incorporated in information transmission equipment and optical fibre cables.