Use numbers followed by a period in vertical text. In professional writing refer to yourself as the writer or the author. Avoid using first personal references such as I, me, we, or us. When an individual conducts such a self-appraisal, he is much stronger. Abbreviations cannot be used at the beginning of a sentence.
Headings provide the reader with a cognitive map.
Most papers will have one to three levels. Short papers may use Level 1 only. Indented, underlines, lowercase paragraph heading ending with a period.