This standard specifies the test requirements for cords including reference cords used in a controlled (Category C) environment according to IEC 61753-1, where the connectors already comply with the Category C requirements of IEC 61753-1. The tests selected are a subset of the connector tests from IEC 61753-1 appropriate for requalification with additional requirements relevant to cords and the connector/cable interface. The cords consist of simplex or duplex fibre optic cable terminated at each end of the cable with singlemode fibre optic connector plugs with cylindrical ferrules. The operational wavelength range is between 1260 nm and 1625 nm. Short length cords are used as test samples as the attenuation of the cord and the temperature cycling performance will be affected by longer lengths of cable. Any qualification of a cord whose length is greater than 5 m should take these factors into account. The relevant requirements for the mechanical interface of connector sets are covered by the IEC 61754 series. The relevant requirements for performance of connector sets are covered by the IEC 61753 series. The relevant requirements for fibres are covered by IEC 60793-2-50. The relevant requirements for cables for cords are covered by IEC 60794-2-50.