一、Courtesy 禮貌
語言要有禮且謙虛，及時地回信也是禮貌的表現。
例如：
We have received with many thanks your letter of 20 May, and we take the pleasure of sending you our latest catalog. We wish to draw your attention to a special offer which we have made in it.
You will be particularly interested in a special offer on page 5 of the latest catalog enclosed, which you requested in your letter of 20 May.
二、Consideration 體諒
寫信時要處處從對方的角度去考慮有什么需求，而不是從自身出發，語氣上更尊重對方。
例如：
“You earn 2 percent discount when you pay cash. We will send you the brochure next month. ”就比 “We allow 2 percent discount for cash payment. We won't be able to send you the brochure this month.” 要好。
三、Completeness 完整
一封商業信函應概況了各項必需的事項，如邀請信應說明時間、地點等，確忌寄出含糊不清的信件。
四、Clarity 清楚
意思表達明確，要注意：
（一）避免用詞錯誤：
例如：As to the steamers sailing from Hong Kong to San Francisco, we have bimonthly direct services.
此處bimonthly有歧義：可以是twice a month 或者once two month.故讀信者就迷惑了，可以改寫為：
1.We have two direct sailings every month from Hong Kong to San Francisco.
2.We have semimonthly direct sailing from Hong Kong to San Francisco.
3.We have a direct sailing from Hong Kong to San Francisco.
（二）注意詞語所放的位置：
例如：
1. We shall be able to supply 10 cases of the item only.
2. We shall be able to supply 10 cases only of the item.
前者則有兩種商品以上的含義。
（三）注意句子的結構：
例如：
1.We sent you 5 samples yesterday of the goods which you requested in your letter of May 20 by air.
2.We sent you, by air, 5 samples of the goods which you requested in your letter of May 20.
五、Conciseness 簡潔
（一）避免廢話連篇：
例如：
1.We wish to acknowledge receipt of your letter...可改為：We appreciate your letter...
2.Enclosed herewith please find two copies of...可改為: We enclose two copies of...
（二）避免不必要的重復：
（三）短句、 單詞 的運用：
Enclosed herewith----->enclosed
at this time----->now
due to the fact that----->because
a draft in the amount of $1000----->a draft for $1000
六、Concreteness 具體
七、Correctness 正確
