GUIDE 59 Second edition 2019-08 Licensed copy: Imperial College , Imperial College London, Version correct as of 30/08/2019 IsO and IEC recommended practices for standardization by national bodies Pratiques de normalisation recommandées par I'sO et I'IEC a leurs organismes nationaux Reference number IEC IS0/IEC GUIDE 59:2019(E) s @IS0/IEC2019 IS0/IEC GUIDE 59:2019(E) , Imperial College London, Version correct as of 30/08/2019 Licensed copy: Imperial College , COPYRIGHTPROTECTEDDOCUMENT @I IS0/IEC2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0/IEC 2019 - All rights reserved