This Technical Specification gives guidance for the assessment of conformity of materials, products, joints and assemblies in accordance with the applicable part(s) of EN 12666 intended to be included in the manufacturer's quality plan as part of the quality management system and for the establishment of third-party certification procedures. NOTE 1 It is recommended that the quality management system conforms to or is no less stringent than the relevant requirements to EN ISO 9001:2008. NOTE 2 If third-party certification is involved, it is recommended that the certification body is accredited to EN 45011, EN 45012 or EN ISO/IEC 17021, as applicable. NOTE 3 In order to help the readers, a summary of the test regime is given in Annex A. In conjunction with EN 12666-1 (see Foreword) this document is applicable to piping systems made of polyethylene (PE): non-pressure underground drainage and sewerage outside the building structure (application area code "U"), reflected in the marking of products by "U", and for non-pressure underground drainage and sewerage for both buried in the ground within the building structure (application area code "D") and outside the building structure (application area code "U"), reflected in the marking of products by "UD".