Good morning. We have some electrical control panels that are going into a CI/D2 location. These panels were designed with components that are all rated for this environment. The customer wants CI/D2 listed on the front label of the electrical panel. Our panel shop says to do this, the panel must conform to UL 1203. Must UL1203 be adhered to if they label the panel as CI/D2? It appears it is a Standard for Explosion-Proof and Dust-Ignition-Proof Electrical Equipment? Thanks in advance.