The purpose of this Document is to define: a) The general requirements concerning the choice, recognition, use and conservation of standards used in the field of legal metrology; and b) Principles concerning the preparation of the documentation for these standards in order to ensure traceability of measurement results. This Document concerns reference and working standards, and is in conformity with ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories [1]. This Document does not concern primary standards, national standards, international standards, or any special standards and may also be used by calibration laboratories