IEC 61755-3-31:2015 defines certain dimensional limits of an angled PC rectangular polyphenylene sulphide (PPS) ferrule optical interface in order to meet specific requirements for fibre-to-fibre interconnection. Ferrules made from the material specified in this standard are suitable for use in categories C, U, E, and O as defined in IEC 61753-1. Ferrule interface dimensions and features are contained in the IEC 61754 series, which deals with fibre optic connector interfaces. Keywords: dimensional limits of an angled PC rectangular polyphenylene sulphide (PPS) ferrule optical interface, fibre-to-fibre interconnection