GoO equivalency to Green-e Standard

Dear All, for an Italian project I need to assess the equivalency between Guarantee of Origin issued by a National energy Authority (GSE) and the Green-e standard. First of all, I'd like to ask if the issue has already been tackled and if an official document, stating the equivalency, has already been draft. I couldn't find it, though. Since the Italian GoO certificate have been regulated according to the European Directive 2009/28/EC, has the issue already been considered at a European level? Is it part of the ACPs mentioned by Marcus? If not the case, is the Green-e Energy Standard v2.3, as reported in the credit description, still the reference standard or the new version 2.4 should be employed? Thank you in advance for any comment and suggestion.