Licensing regulations in both developed and developing countries severely limit the areas in which non-nationals may practice law. By and large, foreign law firms are, in these cases, only permitted to provide advice on their respective national law or on multinational aspects of the law. Appearances in court proceedings are generally still excluded. Furthermore, an elaborate screening and reviewing process can make it difficult to obtain work permits. In a number of countries, citizenship of the country is required for inscription on the professional register, which is necessary in order to practice.