The question, if a mark using a declaration of origin may be protected under trademark law, has to be distinguished from the question concerning the general legitimacy of the use of declarations of origin. Not every mark is prohibited, which is not registered due to certain reasons and therefore receives no protection under trademark law against its use by third parties. The Swiss legal system on trademarks establishes the principle, according to which the use of declarations of origin is prohibited, if such declarations are incorrect. The Federal Law on Unfair Competition rules that is against the law, i.e. unfair, to make incorrect or misleading declarations about goods, works or services. Furthermore the Federal Law on Foods rules that the advertised quality or consistence as well as all other declarations concerning a food must be true and not in any way deceptive.
You will find the summary of a current decision in this matter in our News area (Unfair use of the designation "Switzerland") or as full text version (in German only: Decision of the Swiss Federal Court 4C.361 dated 22 February 2006).