Comprehensive Guide & Reference: Title Capitalization Rules by Style Guide
Headline capitalization rules vary significantly between academic publishing, journalism, and technical documentation. Compare rules across APA, Chicago, MLA, and AP style.
1. Quick Comparison Matrix
| Style Guide | Preposition Rule | Subtitles After Colon | Common Use Case |
|---|---|---|---|
| APA 7th Edition | Capitalize words ≥ 4 letters (e.g. With, From) | Always capitalized | Scientific papers, psychology, social sciences, software blogs. |
| Chicago (CMOS) | Lowercase all prepositions regardless of length | Always capitalized | Book publishing, historical essays, humanities literature. |
| MLA 9th Edition | Lowercase all prepositions, articles, conjunctions | Always capitalized | Literature, arts, humanities, academic dissertations. |
| AP Style | Capitalize prepositions ≥ 4 letters | Always capitalized | News media, journalism, press releases, public relations. |
2. Universal Capitalization Rules
- First and Last Words: Always capitalize the first and last word of a headline regardless of what part of speech it is.
- Subtitles: Always capitalize the first word following a colon (
:) or em-dash (—). - Verbs: Always capitalize verbs, including short forms of "to be" (Is, Are, Was, Be, Been).