In this paper we report on the experience gathered in producing two gold-standard alignment datasets between the European Union thesaurus EuroVoc and two other notable resources adopted in legal environments: the thesaurus of the Italian Senate TESEO and the IATE European terminological resource. The realization of these two resources has been performed in the context of the PMKI project, an European Commission action aiming at creating a Public Multilingual Knowledge management Infrastructure to support e-commerce solutions in a multilingual environment. As of the numerous lexical and terminological resources involved in this project, ontology and thesaurus alignment and, as a consequence, the evaluation of automatically generated alignments, play a pivotal role for the success of the project.