This document sets forth telecom operators', other service providers' and manufacturers' view of proposed technical requirements and characteristics of single mode optical fibres and cables for duct and direct buried installation. This specification includes proposed functional mechanical, environmental and optical requirements, recommended features, and test methods for assessing the product against the stated requirements. The specified test methods where applicable, are those referenced in EN 60794-1-1 "Optical fibre cables - Part 1-1: Generic specification - General" and described in detail in EN 60794-1-2 "Optical fibre cables - Part 1-2: Generic specification - Basic optical cable test procedures". The requirements of this specification shall be used in conjunction with EN 60794-3 "Optical fibre cables - Part 3: Duct, buried and aerial cables - Sectional specification" and EN 60794-3-10 "Optical fibre cables - Part 3-10: External cables - Duct and directly buried optical telecommunication cables - Family specification". Multimode fibre requirements are not addressed in this document.