It is a typical business style letter that should be written in a simple language that is easy to comprehend. (bestcoverletters.com)
If you are corresponding with someone you already have a good working relationship with, the modified block style letter is a good one to use. (gingersoftware.com)
If you teach young students, you might have prepared the pages in advance or cut out bulletin - board style letters for them to paste to their pages. (educationworld.com)