Hyphenated and Dash Compounds in Title Case
Hyphens and dashes are not interchangeable in title-case logic. Chicago 18 changed the treatment of later elements in prefix-based hyphenated compounds, while an em dash can act like a parenthetical or subtitle-like boundary depending on structure.
Treat hyphenated compounds according to the style’s compound rules, not as one undivided word. In Chicago 18, later elements in a prefix-based hyphenated compound follow the general capitalization rule; a spaced or punctuation dash should be parsed as a boundary instead of rewritten as a hyphen.
Key details
Important caveats
Automation boundary
This guide safely covers reviewed prefix patterns and spaced dash boundaries but does not claim a complete compound parser for arbitrary technical or lexical compounds.
Dash Boundary
Chicago’s Q&A compares parentheses with an em dash and shows that the punctuation can delimit a parenthetical structure without changing the grammatical rule for the words inside.
Further guidance
Chicago 18 Change
Chicago’s 18th-edition change summary says subsequent elements in a hyphenated term beginning with a prefix are now capitalized according to the general title-capitalization rule.
Practical Application
Treat a hyphenated compound and a phrase separated by an em/en dash as different structures. Apply compound rules to hyphenated words, while treating a dash as a punctuation boundary that may begin a new title segment depending on the governing style and syntax.
Reader Check
Is the mark joining parts of one compound word, or is it a dash separating larger syntactic units?
Worked Example
Do not rewrite “Risk–Benefit Analysis” or “Planning—What Comes Next” as though every dash were a hyphen; preserve the mark and then apply the selected style’s capitalization rules to the resulting structure.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Headlines and Titles of Works — Chicago Q&A (opens in a new tab)The Chicago Manual of Style / University of Chicago Press · Chicago title-case rules and current-edition updates
- Title case capitalization (opens in a new tab)American Psychological Association · APA title-case rules
- How should I capitalize the title of a handout? (opens in a new tab)MLA Style Center / Modern Language Association · MLA title-style capitalization
- What's New in the 18th Edition (opens in a new tab)The Chicago Manual of Style / University of Chicago Press · Chicago 18 title-case terminology and five-letter-preposition change
- Headlines and Titles of Works — parentheses in title case (opens in a new tab)The Chicago Manual of Style / University of Chicago Press · Chicago guidance that punctuation such as parentheses is normally ignored when applying title case