1. Block format: In this format, all text is aligned to the left margin with single spacing between paragraphs and double spacing between sections.
2. Modified block format: Similar to block format, but with the date and closing aligned to the right margin. The rest of the text is aligned to the left margin.
3. Semi-block format: Similar to block format, but with the date and closing aligned to the center of the page. The rest of the text is aligned to the left margin.