References are either specific (identified by date of publication and/or edition number or version number) or non-specific.• For a specific reference, subsequent revisions do not apply.• Non-specific reference may be made only to a complete document or a part thereof and only in the following cases:- if it is accepted that it will be possible to use all future changes of the referenced document for thepurposes of the referring document;- for informative references.Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference.For online referenced documents, information sufficien