IEC 60794-3-11:2010 sets forth technical requirements and characteristics of single-mode optical fibre cables for duct and direct buried installation. This specification includes functional mechanical, environmental and optical requirements, recommended features and test methods for assessing the product against the stated requirements. The requirements of this specification supplement those of IEC 60794-3 and IEC 60794-3-10. The main changes with respect to the previous edition are as follows: - the title of the specification has been updated to include lashed applications; - the fibres specification clause (subclause 5.2.2) has been enlarged to include fibres types B6_a.