Appeal letter can be used in situations where you are seeking some change or rectification or in case you are looking for some form of help. In any case, it follows a business letter format.
It is important to write appeal letters on a formal letter-head as they help to establish your credentials. Begin the letter by introducing yourself and the purpose of your writing. Keep the tone of the letters polite and cordial.
While writing appeal letters, it is best to keep emotional statements at bay and stick to facts and logic. Elaborate your appeal in a consistent and rational manner without losing track of your aim. As you expect action in some form or the other, your line of argument should persuade the reader in that direction.
Keep the letters short, as most people do not have patience to through elaborate letters. The concluding paragraph must reiterate your cause. Once again put forth your appeal and the need for action. Sign off after thanking the reader for going through your letter.