This part of IEC 61756 covers general information on the subject of fibre management system (FMS) interfaces. It includes references, document structure details, definitions and the rules under which a FMS interface is created. This interface standard defines a fibre management system which is part of an optical network. It provides facilities for the direct exchange of optical signals between the incoming and outgoing fibre optic cables. In order to comply with the standard, the optical functionality, physical, geometrical and mechanical requirements shall be met. These facilities comprise functional and installation aspects for fibres or ribbons like storage, fibre routing, identification, interconnection, reconfiguration, application of passive and active components, protection and traceability. The fibre management system allows different degrees of physical separation of optical circuits. This is in order to reduce the risk of disturbing other circuits that do not belong to the same group as the ones that are to be manipulated. Depending on the grouping, guiding and splicing of the fibres from incoming and outgoing cables, the fibre management system can be a single circuit, a single element or a multiple element management system. Single circuit management describes a management system where one or more fibres of a cable element are spliced and/or stored in individual trays. Single element management describes a management system where all fibres of a cable element are spliced and/or stored in individual trays. Multiple element management describes a management system where fibres from more than one cable element are spliced and/or stored in individual trays. The fibre management system shall be independent from one specific application or housing. It is designed in a way to allow the use for several applications in different housings, e.g. a single circuit management system can be used in a closure, enclosure and open rack. This specification is related to both singlemode and multimode fibres. To fulfil the mentioned functions, a fibre management system is normally integrated in an enclosure, e.g. a closure, case or cabinet or it is part of an open access system like an optical distribution frame or rack.