This part of IEC 61753 contains the minimum initial test and measurement requirements and severities which a fibre-optic pigtailed wide wavelength division multiplexing (WWDM) device for monitoring passive optical networks (PON) using an optical time-domain reflectometer (OTDR) satisfies in order to be categorised as meeting the requirements of category C (indoor controlled environment), as defined in Annex A of IEC 61753-1:2018. WWDM is defined in IEC 62074-1.