This part of IEC 60794 is a family specification that covers outdoor microduct optical fibre cables for installation by blowing and the associated microducts, which together make up a microduct optical fibre cable system. Although primarily designed for use with outdoor microduct applications, the cable products specified herein may be used individually for short lengths in other applications as agreed upon between supplier and customer. These may include short runs inside a building or in other outdoor applications, such as a transition between separate (unconnected) microduct systems, or from a microduct system to some other protective structure such as a cable conduit or tray. Systems built with components covered by this standard are subject to the requirements of IEC 60794-5 where applicable. Annex A shows examples of microduct optical fibre cables and microducts. Annex B describes a blank detail specification for outdoor microduct optical fibre cables and the associated microducts, and incorporates some minimum requirements. Detail product specifications may be prepared on the basis of this family specification using Annex B as a guide. Annex C provides normative requirements for microduct optical fibre cables. The parameters specified in this standard may be affected by measurement uncertainty arising either from measurement errors or calibration errors due to lack of suitable standards. Acceptance criteria should be interpreted with respect to this consideration. The number of fibres and microducts tested shall be representative of the microduct optical fibre cable design and should be agreed between customer and supplier.