Normative references

This page gives guidance on how to use the Normative references.


A document to which reference is made in the standard in such a way as to make it indispensable for the application of the standard.


2.1 The applicable rules shall be strictly followed. The CEN-CENELEC Management Centre (CCMC) has the authority to stop documents that are not in line with these rules.

2.2 Normative reference shall only be made to documents that are publicly available.

In principle, any referenced documents should be those published by CEN, CENELEC, ETSI, ISO and IEC (i.e. European or international standards). In exceptional cases and when it is not possible to include the relevant text in full nor to use European or international standards, the use of other documents as normative references is accepted, provided that the requirements and the special procedure of Clause 4 have been complied with.

2.3 European Standards (EN) shall not contain normative references to:

  • directives, their essential requirements and/or elements of directives;  
  • documents that are not publicly available; 
  • documents which only serve for information;
  • documents only used as a reference during the preparation of the standard. 

Such documents can be listed in a 'Bibliography'.

ENs specifying requirements for a product shall not contain normative references to manufacturing system requirements (e.g. EN ISO 9001, 14000 or related series standards) or certification requirements.

2.4 The number of normative references in an EN shall be limited to the minimum needed for the application of the standard.

2.5 No distinction shall be made between harmonized and non-harmonized standards as far as normative references are concerned (the same rigour shall be applied).


3.1 Both dated and undated references are allowed.

3.1.1 For dated references, the date shall represent the year of publication. In case of references to Enquiry drafts, the year of issue to the Enquiry stage is used. Subsequent amendments to, or revisions of any of these publications do not apply.


  • References to enquiry drafts are discouraged.
  • Use of the most recent edition of the normative documents is encouraged.
  • References to specific divisions or subdivisions, tables and figures of another document are always dated.
  • A dated reference to a published document for which more than one edition is published in the same calendar year is to include the month e.g. :2013-03.

3.1.2 Undated references may be made only to a complete document and only when it will be possible to use all future versions of the document referred to for the purposes of the referring standard.

For undated references, the latest edition of the referenced document (including any amendments) applies. It is the task of the TC to check and confirm that the subsequent versions of the document referred to can be used.

  If references to undated prENs or ENs are included in an EN developed in the framework of a New Approach Directive, TC secretaries need to be aware that the European Commission might not wish to cite that EN in the Official Journal.

3.2 It is possible to make normative reference to drafts (prENs) provided that such drafts do not refer themselves to documents that have not yet reached CEN Enquiry stage. As with published ENs, normative reference to prENs may be dated (year of issue to the Enquiry stage) or undated.

3.2.1 The Technical Board (BT) asks TCs to avoid as far as possible making reference to draft standards in the finalization of FprENs at Formal Vote stage.

3.2.2 If during the preparation of a document referring to a prEN, this referenced prEN is adopted as an EN, reference shall be made to the EN. CCMC is authorized to update this automatically, provided that it has been explicitly confirmed by the Secretary of the responsible CEN technical body that it does not result in any technical change to the document in question.

3.2.3 CEN Members should keep prENs available and supply them on request.


4.1  Proposal

Requests for the use of a normative reference to documents other than those developed by CEN, CENELEC, ETSI, ISO and IEC shall be submitted to the TC for approval. When receiving such a request, the TC Secretary shall:

  • remind the TC that normative reference to documents other than those developed by CEN, CENELEC, ETSI, ISO and IEC may be made only in exceptional cases, and has to be fully justified;
  • ensure the evidence that the issuing organization grants a free translation, reproduction and distribution of the referenced document for CEN purposes and makes the referenced documents available to the public on a fair and reasonable basis; 
  • inform the issuing organization of the referenced document of its intended use and request this body to inform the TC Secretariat of any change of status of the document (e.g. revision, withdrawal, amendment).

NOTE: See Clause 3.3 of the Guidance document 'Copyright' in cases where it is decided to reproduce part or all of the text and not use a normative reference.

4.2  Decision

When taking the decision to refer to documents other than those developed by CEN, CENELEC, ETSI, ISO and IEC, the TC shall:

  • ensure that no suitable CEN, CENELEC, ETSI, ISO or IEC documents are available;
  • confirm that there is a necessity to refer to a document other than those developed by CEN, CENELEC, ETSI, ISO and IEC; 
  • confirm that it is impractical to include the relevant text in full; 
  • justify the need for making reference to a document other than those developed by CEN, CENELEC, ETSI, ISO and IEC;
  • ensure and confirm that the referenced document shall:
    - have wide acceptance;  
    - not be in contradiction with the European legislation, nor create regulatory problems when the EN is implemented by CEN/CENELEC members;  
    - have been prepared in accordance with the principles set in the ISO/IEC Guide 59 - Code of Practice for Standardization (with the definitions of EN 45020) and in the ISO/IEC Directives;  
    - have clearance in respect of possible IPR (Intellectual Property Rights) issues as prescribed in CEN-CENELEC Guide 8;  
    - not be a draft, but an adopted document with an identified and dated issue;  
    - be publicly available in official CEN/CENELEC languages, at least in English.

The approval shall be formulated in the form of a TC decision (to be approved by simple majority) and transmitted to CCMC following the procedure for Delegated decisions.
When at least one of the criteria is not fulfilled or in case of doubt, the matter shall be referred to BT for decision.

4.3. Maintenance

4.3.1 When the document is accepted as normative reference, the TC Secretariat shall:

  • ensure that, in the EN, normative reference is made to an identified and dated issue of the referenced document as stated in the TC decision; 
  • indicate the issuing organization of the referenced document and the source of supply in a footnote to the EN; 
  • monitor the further development of the referenced document (e.g. amendment, revision, withdrawal);
  • keep a copy of the referenced document.

4.3.2  The TC shall examine whether ISO, IEC, CEN, CENELEC and/or ETSI (as appropriate) would be able to prepare a suitable new standard or to revise an existing standard that has been considered inappropriate so far. The EN or international standard could then replace the referenced document not published by ISO, IEC, CEN, CENELEC and ETSI.


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