IEC 61753-051-02 Ed. 1.0 b:2022

This part of IEC 61753 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.