通常国际商务交流中的书信格式分为四种，选择用哪种格式看写信人的爱好。
Modified-Block Letter Format
In this format each typed element - except the date an d the signature block - begins at the left-hand margin. The date may be backspaced from the right margin point to align at the right margin; it may be centered, Ｏr it may begin at the center. （日期可以放在最右边，也可以放在中间，或是从中间向右写。）The most attractive placement of the date, however, may depend on the letterhead design.
Semi-Block Letter Format
This format resembles to the modified block in every other regard except that the paragraphs in the body of the letter are indented.（这种格式的排版，除了书信主体每段首行要空格以外，其他均类似于Modified-Block Letter。）
Full-Block Letter Format
The full block format is illustrative of the trend toward simplicity an d ease of use. All lines, including the date an d the signature block, begin at the left margin. Paragraphs are always blocked. （段段之间通常空行。）
This letter arrangement is more efficient than the modified block Ｏr the semi-modified block in that no extra time is required for paragraph indention Ｏr placement of the date an d closing lines. In addition, many writers believe that the full-block arrangement provides an attractive, business-like appearance.
Simplified Letter Format
As in the full-block format, all lines in the simplified format begin at the left-hand margin. It leaves out the conventional salutation an d complimentary close, invariably containing a subject line in lieu of the salutation indicating what the letter is about（在本来该写称呼的地方增加一句表明信的内容的主题句）. Supporters of the simplified format argue that salutation an d complimentary close contribute little to the message except for a waste of time. Others, however, are reluctant to omit the tonal qualities of the two components because they have been used routinely over years an d readers expect them.
