IEC 61753-051-02:2022 contains the minimum initial test and measurement requirements and severities which plug-receptacle style single-mode fibre fixed optical attenuators need to satisfy in order to be categorized as meeting the requirements of category C – Controlled environments, as defined in IEC 61753-1:2018, Annex A. This first edition cancels and replaces IEC 61753-051-3 published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 61753‑051‑3:2013:;change the category from U to C and the test items and their conditions according to IEC 61753-1;change the requirements reflecting the survey results.