In this presentation standards and guidelines for grid-forming inverters from different countries world wide are reviewed and compared. The analysis includes technical requirements as well as the procedure for proving compliance. Based on the review, clear recommendations for drafting new grid-forming guidelines are presented (e.g. for countries that do not have a standard yet). The importance of unambiguous wording, including functional, quantitative and dynamic requirements and the alignment with international best practices are highlighted. Finally, concrete texts for new guidelines, considering the before mentioned criteria, are suggested.