This standard defines the fields of application for which the use of verified (*) measuring instruments is recommended. Under the heading “Commentary”, the standard gives explanations, reasons, and examples intended to facilitate understanding of the text. In addition, under the heading “Examples”, it indicates a number of measuring instruments which could be considered suitable subjects for verification. This standard, in conjunction with other GSO standard, concerning “metrological law”, legal units of measurements”, etc., can serve as a starting point for developing legislation by the appropriate bodies. Even jurisdictions which already have a well developed system of legal metrology may consider some aspects of this standard if they want to extend their system of legal metrology into additional fields (for example, official activities, medicine, or environmental protection). The standard stresses the need to utilize instruments that have been verified. The measurement assurance techniques that verify the accuracy of the entire measurement by assessing the results of the measurement process, such as those described in standard developed by the Reporting Secretariat SP 22-Sr 6, are also consistent with the intent of this standards .