162.According to the 1996 Guidelines, certification “shall be made” under Section 609（b）（2）（A） and （B） if an exporting country's program includes a requirement that all commercial shrimp trawl vessels operating in waters in which there is a likelihood of intercepting sea turtles use, at all times, TEDs comparable in effectiveness to those used in the United States. Under these Guidelines, any exceptions to the requirement of the use of TEDs must be comparable to those of the United States program. Furthermore, the harvesting country must have in place a “credible enforcement effort”. The language in the 1996 Guidelines is mandatory: certification “shall be made” if these conditions are fulfilled. However, we understand that these rules are also applied in an exclusive manner. That is, the 1996 Guidelines specify the only way that a harvesting country's regulatory program can be deemed “comparable” to the United States’ program, and, therefore, they define the only way that a harvesting nation can be certified under Section 609（b）（2）（A） and （B）. Although the 1996 Guidelines state that, in making a comparability determination, the Department of State “shall also take into account other measures the harvesting nation undertakes to protect sea turtles”, in practice, the competent government officials only look to see whether there is a regulatory program requiring the use of TEDs or one that comes within one of the extremely limited exceptions available to United States shrimp trawl vessels.