This part of IEC 60793-2 is applicable to optical fibre categories A4a, A4b, A4c, A4d, A4e, A4f, A4g and A4h. These fibres have a plastic core and plastic cladding and may have step-index, multi-step index, or graded-index profiles. The fibres are used in information transmission equipment and optical fibre cables. Table 1 summarizes some of the salient characteristics and applications of these fibres. In addition to the applications shown in Table 1, other applications for A4 fibres include, but are not restricted to, the following: support for short reach high bit-rate systems in telephony, distribution and local networks, carrying data, voice and/or video services and on-premises intrabuilding and interbuilding fibre installations, including LANs, PBXs, video, various multiplexing uses, and miscellaneous related uses, such as consumer electronics and industrial and mobile networks. Three types of requirements apply to A4 fibres: • general requirements, as defined in IEC 60793-2; • specific requirements common to category A4 multimode fibres covered in this standard and that are given in Clause 3; • particular requirements applicable to individual fibre types or specific applications and that are defined in this standard in the normative family specification annexes.