This part of IEC 60793 is applicable to optical fibre types C1, C2, C3, and C4, as described in Table 1. These fibres are used for the interconnections within or between optical components systems and are optimized to support dense optical connectivity. While the fibres can be overcoated or buffered for the purpose of making protected pigtails, they can be used without overcoating. They can, however, be colour coded.
EN IEC 60793-2-60 ED2
IEC 60793-2-60:2025