商业信函的7个“C”原则

　　写信的原则（Writing Principles）已从原来的3个“C”（Conciseness, Clearness, Courtesy）发展到目前的7个“C”：Completeness, Clearness, Concreteness, Conciseness, Correctness, Courtesy, Consideration

　　实例:

　　Dear Sirs,

　　With reference to your letter of April 9, we are pleased to accept your offer of 100 tons of Copper Wire as per your Offer Sheet No.8/070/02B. Please go ahead and apply for your Export Licence. As soon as we are informed of the number of the Export Licence we will open the L/C by cable.