A slash can join alternatives, words, phrases, or other structures, so the slash itself is not enough information to decide capitalization around it. This guide therefore treats unresolved slash constructions as structural cases rather than splitting and guessing.
ReviewedEvidence4 sourcesSectionWriting & Style
Quick answer
Preserve the slash as written. If the grammar on both sides has not been identified, do not let an automatic title-case converter guess whether either side begins a new structural unit.
Key details
Automation Statusstructural review
Punctuationslash
Rule Familyslash-structure
Important caveats
Automation boundary
This guide keeps slash constructions left unresolved in named-style automation until phrase/alternative structure is parsed.
Further guidance
Slash Semantics
Chicago notes that a slash may divide words or longer phrases and can mark alternatives; those are structurally different uses.
Spacing
Chicago uses no spaces when a slash divides two words, and spaces when it separates phrases or a word from a phrase.
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.
Colons, semicolons, and dashes can create capitalization boundaries in titles, while quotation marks and parentheses may introduce embedded structures that require additional analysis. This guide separates punctuation-boundary detection from word-class decisions so it can explain when a new segment begins and when it must leave the result unresolved.
Quotation marks do not by themselves decide which words are capitalized. A converter must distinguish harmless outer quotation punctuation from an embedded title or quoted structure that may need its own capitalization and formatting rules.
Apostrophes can mark possession, contractions, or omitted initial letters, and those uses should not be confused with quotation marks. Chicago also has specific title-case examples for initial-apostrophe contractions and for the compound form “O’Clock.”
A title appearing inside another title has its own identity and may need quotation marks, italics, or language-specific treatment. Flattening the inner title into the outer title’s token stream can destroy both formatting and capitalization.
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.
A colon can create a title/subtitle boundary, but nested punctuation still needs structural handling. Chicago capitalizes the first word after a title/subtitle colon; repeated or nested colons should therefore be parsed as boundaries rather than treated as ordinary word punctuation.
Parentheses can appear in headings and titles without creating a new capitalization system. Chicago says the parentheses themselves are normally ignored when title case is applied, so words inside still follow their grammatical title-case rules.
Chicago 18 changed how later elements in prefix-based hyphenated compounds are capitalized: each component now follows the general title-case rule. Safe automatic treatment still requires recognizing that the hyphen truly joins a reviewed prefix compound.
