A petition letter should contain the following information: a concise description of the situation at hand, a suggestion of a way forward and the reason for the recommendation. It should also include a logical call to action.
Most appeal letters are written when the writer is upset. However, this is not the time for the author to vent her anger and frustrations on the recipient. A petition letter is an official document and should follow the layout of a formal letter; the writer needs to be aware of her word choices. On the same note, all the information contained in the letter should be relevant to the topic.
When writing this kind of a letter, the petitioner should be fully cognizant of her objective: what she wants to change. Also, as a petitioner, she should make sure she understands the policies of the institution she is addressing; some systems do not allow petitions. While it is not advisable to use offensive words in the letter, the petitioner can still express her genuine emotions in a more measured and reasonable way.
A petition should only include documents and facts that relate to the situation. Any unnecessary information may distract from the petitioner's points, and reduce the chance of having her grievances dealt with.