LETTER FORMATS

      Business writers today generally favor the block or simplified letter formats for two reasons:

1.  Moving all elements flush left is easier for typists/word processors.
2. Indenting is unnecessary, since one blank line is routinely left between paragraphs.

     The modified block and semiblock formats feel less formal than the block format. The choice of formats for business correspondence should be consistent with the image an organization desires to project.

     Using the simplified format reduces the potential for the inadvertent use of sexist language, since the salutation is omitted. In the business world, the traditional greeting and closing are unnecessary.

The Formats

Block style There is Unindented paragraphs. All letter elements are flush with the left margin.

Modified block style There is Unindented paragraphs. The return address,reference line, date, complimentary closing, and signature block are right of center. Remaining elements are flush with the left margin.

Semiblock style There is Indented paragraphs (usually an equivalent of five spaces). The return address, reference line, date, complimentary closing, and signature block are right of center. Remaining elements are flush with the left margin.

Simplified style There is Unindented paragraphs. The salutation and complimentary closing are omitted. All elements are flush with the left margin.

Full Block style There is All elements of the letter are flush left.

reference: http://www.kcitraining.com/styleguide/letform.html