Fibre optic interconnecting devices and passive components – Performance standard – Part 021-3: Single-mode fibre optic connectors for category U – Uncontrolled environment (Edition 1.0)
This part of IEC 61753 defines minimum initial test and measurement requirements and severities which a single-mode connector@ either part of a pigtail@ or part of a cord@ must satisfy in order to be categorized as meeting the IEC standard category U (uncontrolled environment).