A Harmonization Document (HD) is a normative document made available by CENELEC in the three official languages.
The elaboration of a HD includes a public enquiry, followed by an approval by weighted vote of CENELEC national members and final ratification. The Harmonization Document is announced at national level and every conflicting national standard is withdrawn. Having fulfilled these obligations, a member is free to maintain or issue a national standard dealing with a subject within the scope of the HD, provided that it is equivalent in technical content. The number, title and date of each such national standard shall be notified to the CEN-CENELEC Management Centre. A Harmonization Document does not conflict with any other EN and HD and is periodically reviewed.
During the elaboration and whole lifetime of the Harmonization Document, standstill applies.
The preparation, the approval and the review of an HD follow the same procedure as that given for an EN.