This part of 60794 specifies the requirements of single-mode optical fibre cables and cable elements which are intended to be used primarily in public telecommunications networks. Other types of applications requiring similar types of cables can be considered. Requirements for cables to be used in ducts, for directly buried application, aerial cables and cables for lake and river crossings are included in this standard. For aerial application, this standard does not cover all functional aspects of cables installed in the vicinity of overhead power lines. In the case of such application, additional requirements and test methods may be necessary. Moreover, this standard excludes optical ground wires and cables attached to the phase or earth conductors of overhead power lines. For cables for lake and river crossings, this standard does not cover methods of cable repair, nor repair capability, nor does it cover cables for use with underwater line amplifiers.