Institutions such as FEANI generally gain strength, weight and influence with growth. To be efficient, FEANI must however assure an adequate level of homogeneity among its members.
Therefore acceptance criteria have been established which new applicants must prove they fulfill. FEANI being a European Federation, the Guideline for the recognition of European identity helps potential applicants to judge by themselves if they belong to this category.
Countries outside Europe may apply for membership with WFEO.