This part of IEC 61753 defines minimum initial test and measurement requirements and severities which single-mode fibre optic connectors terminated as a pigtail or a patchcord satisfy in order to be categorized as meeting the IEC standard category OP (outdoor protected environment), as defined in IEC 61753-1. If tests were performed on the connectors terminated as pigtails or patchcords for category OPHD, OP+ or OP+HD and the product passed, the product will be automatically qualified or categorized as meeting the IEC standard for category OP. If tests are performed on the connectors terminated as pigtails or patchcords for category OP, and the product passes, the product will be automatically qualified or categorized as meeting the IEC standard for category C or CHD.