寫信的原則（Writing Principles）已從原來的`3個“C”（Conciseness, Clearness, Courtesy）發展到目前的7個“C”：Completeness, Clearness, Concreteness, Conciseness, Correctness, Courtesy, Consideration
例項:
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.
信的本文漢譯
關於你們四月九日涵，我們高興地接受你們第8／070／02Ｂ號報盤單所報100噸紫色銅絲。
請著手辦理申請出口許可證。一經接到出口許可證號碼的通知，當即電開信用證。