This is a container category, gathering organizations which are primarily defined by the identities of their members; e.g., women's organizations; youth organizations; ethnic identities; organizations of organizations. There should be few or no individual articles included here.
Many such organizations may overlap their membership and their subject concerns. For instance, most women's organizations are about women and as well as composed of women members. However, some may have broader subject or membership requirements. When in doubt, list an organization in both relevant category trees to ensure it will be found.