Many colleges require students to follow a specific style guide, such as the manual published by the American Psychological Association, when writing papers. APA formatting is commonly used in the social and behavioral sciences. A style guide provides a consistent set of rules that writers must follow regarding formatting, content and citations. The sixth edition of the APA's "Publication Manual" was published in 2010. The manual includes instructions for properly formatting titles and subtitles, which the APA refers to as "headings" and "subheadings."
Style your main heading, called the Level 1 heading, in text that is centered, bold and capitalized in title case. Title case capitalization means using uppercase letters to begin all major words -- including nouns, verbs, adjectives, pronouns and adverbs -- as well as any conjunctions or prepositions that are four letters or more. All headings other than Level 1 are considered subtitles, or subheadings.
Type your second-level heading flush with the left margin, bold and capitalized in title case.
Compose your third-level heading by indenting one-half inch and typing the heading in bold. Capitalize only the first word and any proper nouns within a third-level heading, and place a period at the end of the heading.
Construct your fourth-level heading by indenting one-half inch and typing the heading in bold italics. Capitalize as you do a third-level heading and place a period at the end.
Generate a Level 5 heading the same way you style a Level 4 heading, removing the boldface.
Do not label any titles or subtitles with numbers or letters.
The beginning of a manuscript is assumed to be the introduction, so do not place an "Introduction" header before it.
Although APA formatting allows for up to 5 heading levels, many papers that are not particularly detailed will only require level 1 and level 2 headings. Use only what you need to organize and explain your ideas clearly.
Follow the guidelines for APA format exactly or the paper is not considered "APA style."