feat(core): create rule to title-case headings (#2297)

* feat(core): introduce `Heading` `TokenKind` * feat(core): create `iter_headings` extension * refactor(core): remove unhelpful tests * chore(core): update snapshots * refactor(core): avoid allocation where possible * feat(core): create rule that enforces title case for headings * fix(core): NP members should be capitalized * fix(core): appease clippy * feat(harper.js): allow `harper.js` to force headings * fix(harper.js): make `organized_lints` similar: allow forced headings * fix(harper.js): appease Biome * feat(chrome-ext): expose title casing in Chrome extension * fix(chrome-ext): content script console bloat * test(core): title_case module more extensively; fix things * refactor(core): remove useless branch * refactor(core): use tokens over characters * refactor(core): use token indices instead of spans
2025-12-05 19:26:55 -06:00 · 2025-12-05 13:35:00 -07:00
parent 1301d20400
commit bfaa324c07
43 changed files with 1181 additions and 344 deletions
--- a/harper-core/src/dict_word_metadata.rs
+++ b/harper-core/src/dict_word_metadata.rs
@@ -43,9 +43,9 @@ pub struct DictWordMetadata {
    pub common: bool,
    #[serde(default = "default_none")]
    pub derived_from: Option<WordId>,
-    /// Generated by a chunker
+    /// Generated by a chunker. Declares whether the word is a member of a nominal phrase.
    pub np_member: Option<bool>,
-    /// Generated by a POS tagger
+    /// Generated by a POS tagger. Declares what it inferred the word's part of speech to be.
    pub pos_tag: Option<UPOS>,
 }

--- a/harper-core/src/document.rs
+++ b/harper-core/src/document.rs
@@ -918,6 +918,7 @@ impl TokenStringExt for Document {
    create_fns_on_doc!(verb);
    create_fns_on_doc!(word);
    create_fns_on_doc!(word_like);
+    create_fns_on_doc!(heading_start);

    fn first_sentence_word(&self) -> Option<&Token> {
        self.tokens.first_sentence_word()
@@ -947,6 +948,10 @@ impl TokenStringExt for Document {
        self.tokens.iter_paragraphs()
    }

+    fn iter_headings(&self) -> impl Iterator<Item = &'_ [Token]> + '_ {
+        self.tokens.iter_headings()
+    }
+
    fn iter_sentences(&self) -> impl Iterator<Item = &'_ [Token]> + '_ {
        self.tokens.iter_sentences()
    }
--- a/harper-core/src/linting/currency_placement.rs
+++ b/harper-core/src/linting/currency_placement.rs
@@ -110,7 +110,7 @@ mod tests {
    #[test]
    fn multiple_dollar() {
        assert_suggestion_result(
-            "They were either 25$ 24$ or 23$.",
+            "They were either 25\\$ 24\\$ or 23\\$.",
            CurrencyPlacement::default(),
            "They were either $25 $24 or $23.",
        );
--- a/harper-core/src/linting/lint_group.rs
+++ b/harper-core/src/linting/lint_group.rs
@@ -185,6 +185,7 @@ use super::touristic::Touristic;
 use super::unclosed_quotes::UnclosedQuotes;
 use super::update_place_names::UpdatePlaceNames;
 use super::use_genitive::UseGenitive;
+use super::use_title_case::UseTitleCase;
 use super::verb_to_adjective::VerbToAdjective;
 use super::very_unique::VeryUnique;
 use super::vice_versa::ViceVersa;
@@ -691,6 +692,9 @@ impl LintGroup {
        out.add("MassPlurals", MassPlurals::new(dictionary.clone()));
        out.config.set_rule_enabled("MassPlurals", true);

+        out.add("UseTitleCase", UseTitleCase::new(dictionary.clone()));
+        out.config.set_rule_enabled("UseTitleCase", true);
+
        out.add_chunk_expr_linter(
            "DisjointPrefixes",
            DisjointPrefixes::new(dictionary.clone()),
--- a/harper-core/src/linting/mod.rs
+++ b/harper-core/src/linting/mod.rs
@@ -198,6 +198,7 @@ mod touristic;
 mod unclosed_quotes;
 mod update_place_names;
 mod use_genitive;
+mod use_title_case;
 mod verb_to_adjective;
 mod very_unique;
 mod vice_versa;
@@ -254,7 +255,8 @@ where

 #[cfg(test)]
 pub mod tests {
-    use crate::{Document, Span, Token, parsers::PlainEnglish};
+    use crate::parsers::Markdown;
+    use crate::{Document, Span, Token};
    use hashbrown::HashSet;

    /// Extension trait for converting spans of tokens back to their original text
@@ -479,7 +481,7 @@ pub mod tests {
        loop {
            let test = Document::new_from_vec(
                text_chars.clone().into(),
-                &PlainEnglish,
+                &Markdown::default(),
                &FstDictionary::curated(),
            );
            let lints = linter.lint(&test);
--- a/harper-core/src/linting/use_title_case.rs
+++ b/harper-core/src/linting/use_title_case.rs
@@ -0,0 +1,69 @@
+use crate::{Document, TokenStringExt, spell::Dictionary, title_case::try_make_title_case};
+
+use super::{Lint, LintKind, Linter, Suggestion};
+
+pub struct UseTitleCase<D: Dictionary + 'static> {
+    dict: D,
+}
+
+impl<D: Dictionary + 'static> UseTitleCase<D> {
+    pub fn new(dict: D) -> Self {
+        Self { dict }
+    }
+}
+
+impl<D: Dictionary + 'static> Linter for UseTitleCase<D> {
+    fn lint(&mut self, document: &Document) -> Vec<Lint> {
+        let mut lints = Vec::new();
+
+        for heading in document.iter_headings() {
+            let Some(span) = heading.span() else {
+                continue;
+            };
+
+            if let Some(title_case) =
+                try_make_title_case(heading, document.get_source(), &self.dict)
+            {
+                lints.push(Lint {
+                    span,
+                    lint_kind: LintKind::Capitalization,
+                    suggestions: vec![Suggestion::ReplaceWith(title_case)],
+                    message: "Try to use title case in headings.".to_owned(),
+                    priority: 127,
+                });
+            }
+        }
+
+        lints
+    }
+
+    fn description(&self) -> &str {
+        "Prompts you to use title case in relevant headings."
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::linting::tests::assert_suggestion_result;
+    use crate::spell::FstDictionary;
+
+    use super::UseTitleCase;
+
+    #[test]
+    fn simple_correction() {
+        assert_suggestion_result(
+            "# This is a title",
+            UseTitleCase::new(FstDictionary::curated()),
+            "# This Is a Title",
+        );
+    }
+
+    #[test]
+    fn double_correction() {
+        assert_suggestion_result(
+            "# This is a title\n\n## This is a subtitle",
+            UseTitleCase::new(FstDictionary::curated()),
+            "# This Is a Title\n\n## This Is a Subtitle",
+        );
+    }
+}
--- a/harper-core/src/parsers/markdown.rs
+++ b/harper-core/src/parsers/markdown.rs
@@ -204,7 +204,16 @@ impl Parser for Markdown {
                    });
                    stack.push(pulldown_cmark::Tag::List(v));
                }
-                pulldown_cmark::Event::Start(tag) => stack.push(tag),
+                pulldown_cmark::Event::Start(tag) => {
+                    if matches!(tag, pulldown_cmark::Tag::Heading { .. }) {
+                        tokens.push(Token {
+                            span: Span::new_with_len(span_start, 0),
+                            kind: TokenKind::HeadingStart,
+                        });
+                    }
+
+                    stack.push(tag)
+                }
                pulldown_cmark::Event::End(pulldown_cmark::TagEnd::Paragraph)
                | pulldown_cmark::Event::End(pulldown_cmark::TagEnd::Item)
                | pulldown_cmark::Event::End(pulldown_cmark::TagEnd::Heading(_))
@@ -575,4 +584,28 @@ Paragraph.
        let parser = Markdown::new(opts);
        let _res = parser.parse_str("//{@j");
    }
+
+    #[test]
+    fn simple_headings_are_marked() {
+        let opts = MarkdownOptions::default();
+        let parser = Markdown::new(opts);
+        let tokens = parser.parse_str("# This is a simple heading");
+
+        assert_eq!(tokens.iter_heading_starts().count(), 1);
+        assert_eq!(tokens.iter_headings().count(), 1);
+    }
+
+    #[test]
+    fn multiple_headings_are_marked() {
+        let opts = MarkdownOptions::default();
+        let parser = Markdown::new(opts);
+        let tokens = parser.parse_str(
+            r#"# This is a simple heading
+
+## This is a second simple heading"#,
+        );
+
+        assert_eq!(tokens.iter_heading_starts().count(), 2);
+        assert_eq!(tokens.iter_headings().count(), 2);
+    }
 }
--- a/harper-core/src/parsers/mod.rs
+++ b/harper-core/src/parsers/mod.rs
@@ -4,6 +4,7 @@ mod collapse_identifiers;
 mod isolate_english;
 mod markdown;
 mod mask;
+mod oops_all_headings;
 mod org_mode;
 mod plain_english;

@@ -12,6 +13,7 @@ pub use collapse_identifiers::CollapseIdentifiers;
 pub use isolate_english::IsolateEnglish;
 pub use markdown::{Markdown, MarkdownOptions};
 pub use mask::Mask;
+pub use oops_all_headings::OopsAllHeadings;
 pub use org_mode::OrgMode;
 pub use plain_english::PlainEnglish;

--- a/harper-core/src/parsers/oops_all_headings.rs
+++ b/harper-core/src/parsers/oops_all_headings.rs
@@ -0,0 +1,49 @@
+use crate::{Span, Token, TokenKind};
+
+use super::Parser;
+
+/// A parser that wraps another, forcing the entirety of the document to be composed of headings.
+pub struct OopsAllHeadings<P: Parser + 'static> {
+    inner: P,
+}
+
+impl<P: Parser + 'static> OopsAllHeadings<P> {
+    pub fn new(inner: P) -> Self {
+        Self { inner }
+    }
+}
+
+impl<P: Parser + 'static> Parser for OopsAllHeadings<P> {
+    fn parse(&self, source: &[char]) -> Vec<Token> {
+        let inner = self.inner.parse(source);
+        let mut output = Vec::with_capacity(inner.capacity());
+
+        output.push(Token {
+            span: Span::default(),
+            kind: TokenKind::HeadingStart,
+        });
+
+        let mut iter = inner.into_iter().peekable();
+
+        while let Some(tok) = iter.next() {
+            let heading_start = if tok.kind.is_paragraph_break()
+                && iter.peek().is_some_and(|t| !t.kind.is_heading_start())
+            {
+                Some(Token {
+                    span: Span::new_with_len(tok.span.end, 0),
+                    kind: TokenKind::HeadingStart,
+                })
+            } else {
+                None
+            };
+
+            output.push(tok);
+
+            if let Some(extra) = heading_start {
+                output.push(extra);
+            }
+        }
+
+        output
+    }
+}
--- a/harper-core/src/title_case.rs
+++ b/harper-core/src/title_case.rs
@@ -6,6 +6,7 @@ use crate::TokenKind;
 use hashbrown::HashSet;
 use lazy_static::lazy_static;

+use crate::Punctuation;
 use crate::spell::Dictionary;
 use crate::{CharStringExt, Document, TokenStringExt, parsers::Parser};

@@ -27,17 +28,46 @@ pub fn make_title_case_chars(
    make_title_case(document.get_tokens(), source.as_slice(), dict)
 }

-pub fn make_title_case(toks: &[Token], source: &[char], dict: &impl Dictionary) -> Vec<char> {
+pub fn try_make_title_case(
+    toks: &[Token],
+    source: &[char],
+    dict: &impl Dictionary,
+) -> Option<Vec<char>> {
    if toks.is_empty() {
-        return Vec::new();
+        return None;
    }

    let start_index = toks.first().unwrap().span.start;
+    let relevant_text = toks.span().unwrap().get_content(source);

-    let mut word_likes = toks.iter_word_likes().enumerate().peekable();
-    let mut output = toks.span().unwrap().get_content(source).to_vec();
+    let mut word_likes = toks.iter_word_like_indices().enumerate().peekable();
+
+    let mut output = None;
+    let mut previous_word_index = 0;
+
+    // Checks if the output if the provided char is different from the source. If so, it will
+    // set the output. The goal here is to avoid allocating if no edits must be made.
+    let mut set_output_char = |idx: usize, new_char: char| {
+        if output
+            .as_ref()
+            .is_some_and(|o: &Vec<char>| o[idx] != new_char)
+            || relevant_text[idx] != new_char
+        {
+            if output.is_none() {
+                output = Some(relevant_text.to_vec())
+            }
+
+            let Some(mutable) = &mut output else {
+                panic!("We just set output to `Some`. This should be impossible.");
+            };
+
+            mutable[idx] = new_char;
+        }
+    };
+
+    while let Some((index, word_idx)) = word_likes.next() {
+        let word = &toks[word_idx];

-    while let Some((index, word)) = word_likes.next() {
        if let Some(Some(metadata)) = word.kind.as_word()
            && metadata.is_proper_noun()
        {
@@ -46,59 +76,87 @@ pub fn make_title_case(toks: &[Token], source: &[char], dict: &impl Dictionary)

            if let Some(correct_caps) = dict.get_correct_capitalization_of(orig_text) {
                // It should match the dictionary verbatim
-                output[word.span.start - start_index..word.span.end - start_index]
-                    .iter_mut()
-                    .enumerate()
-                    .for_each(|(idx, c)| *c = correct_caps[idx]);
+                for (i, c) in correct_caps.iter().enumerate() {
+                    set_output_char(word.span.start - start_index + i, *c);
+                }
            }
        };

-        let should_capitalize = should_capitalize_token(word, source, dict)
+        // Capitalize the first word following a colon to match Chicago style.
+        let is_after_colon = toks[previous_word_index..word_idx]
+            .iter()
+            .any(|tok| matches!(tok.kind, TokenKind::Punctuation(Punctuation::Colon)));
+
+        let should_capitalize = is_after_colon
+            || should_capitalize_token(word, source)
            || index == 0
            || word_likes.peek().is_none();

        if should_capitalize {
-            output[word.span.start - start_index] =
-                output[word.span.start - start_index].to_ascii_uppercase();
+            set_output_char(
+                word.span.start - start_index,
+                relevant_text[word.span.start - start_index].to_ascii_uppercase(),
+            );
        } else {
            // The whole word should be lowercase.
            for i in word.span {
-                output[i - start_index] = output[i - start_index].to_ascii_lowercase();
+                set_output_char(
+                    i - start_index,
+                    relevant_text[i - start_index].to_ascii_lowercase(),
+                );
            }
        }
+
+        previous_word_index = word_idx
+    }
+
+    if let Some(output) = &output
+        && output.as_slice() == relevant_text
+    {
+        return None;
    }

    output
 }

+pub fn make_title_case(toks: &[Token], source: &[char], dict: &impl Dictionary) -> Vec<char> {
+    try_make_title_case(toks, source, dict)
+        .unwrap_or_else(|| toks.span().unwrap_or_default().get_content(source).to_vec())
+}
+
 /// Determines whether a token should be capitalized.
 /// Is not responsible for capitalization requirements that are dependent on token position.
-fn should_capitalize_token(tok: &Token, source: &[char], dict: &impl Dictionary) -> bool {
+fn should_capitalize_token(tok: &Token, source: &[char]) -> bool {
    match &tok.kind {
        TokenKind::Word(Some(metadata)) => {
            // Only specific conjunctions are not capitalized.
            lazy_static! {
                static ref SPECIAL_CONJUNCTIONS: HashSet<Vec<char>> =
-                    ["and", "but", "for", "or", "nor"]
+                    ["and", "but", "for", "or", "nor", "as"]
                        .iter()
                        .map(|v| v.chars().collect())
                        .collect();
+                static ref SPECIAL_ARTICLES: HashSet<Vec<char>> = ["a", "an", "the"]
+                    .iter()
+                    .map(|v| v.chars().collect())
+                    .collect();
            }

            let chars = tok.span.get_content(source);
            let chars_lower = chars.to_lower();

-            let mut metadata = Cow::Borrowed(metadata);
-
-            if let Some(metadata_lower) = dict.get_word_metadata(&chars_lower) {
-                metadata = Cow::Owned(metadata.clone().or(&metadata_lower));
-            }
+            let metadata = Cow::Borrowed(metadata);

            let is_short_preposition = metadata.preposition && tok.span.len() <= 4;

+            if chars_lower.as_ref() == ['a', 'l', 'l'] {
+                return true;
+            }
+
            !is_short_preposition
-                && !metadata.is_determiner()
+                && !metadata.is_non_possessive_determiner()
                && !SPECIAL_CONJUNCTIONS.contains(chars_lower.as_ref())
+                && !SPECIAL_ARTICLES.contains(chars_lower.as_ref())
        }
        _ => true,
    }
@@ -267,4 +325,184 @@ mod tests {
            "I Spoke at WordCamp U.S. in 2025",
        );
    }
+
+    #[test]
+    fn fixes_your_correctly() {
+        assert_eq!(
+            make_title_case_str(
+                "it is not your friend",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "It Is Not Your Friend",
+        );
+    }
+
+    #[test]
+    fn handles_old_man_and_the_sea() {
+        assert_eq!(
+            make_title_case_str(
+                "the old man and the sea",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "The Old Man and the Sea",
+        );
+    }
+
+    #[test]
+    fn handles_great_story_with_subtitle() {
+        assert_eq!(
+            make_title_case_str(
+                "the great story: a tale of two cities",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "The Great Story: A Tale of Two Cities",
+        );
+    }
+
+    #[test]
+    fn handles_lantern_and_moths() {
+        assert_eq!(
+            make_title_case_str(
+                "lantern flickered; moths began their worship",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "Lantern Flickered; Moths Began Their Worship",
+        );
+    }
+
+    #[test]
+    fn handles_static_with_ghosts() {
+        assert_eq!(
+            make_title_case_str(
+                "static filled the room with ghosts",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "Static Filled the Room with Ghosts",
+        );
+    }
+
+    #[test]
+    fn handles_glass_trembled_before_thunder() {
+        assert_eq!(
+            make_title_case_str(
+                "glass trembled before thunder arrived.",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "Glass Trembled Before Thunder Arrived.",
+        );
+    }
+
+    #[test]
+    fn handles_hepatitis_b_shots() {
+        assert_eq!(
+            make_title_case_str(
+                "an end to hepatitis b shots for all newborns",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "An End to Hepatitis B Shots for All Newborns",
+        );
+    }
+
+    #[test]
+    fn handles_trump_approval_rating() {
+        assert_eq!(
+            make_title_case_str(
+                "trump's approval rating dips as views of his handling of the economy sour",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "Trump's Approval Rating Dips as Views of His Handling of the Economy Sour",
+        );
+    }
+
+    #[test]
+    fn handles_last_door() {
+        assert_eq!(
+            make_title_case_str("the last door", &PlainEnglish, &FstDictionary::curated()),
+            "The Last Door",
+        );
+    }
+
+    #[test]
+    fn handles_midnight_river() {
+        assert_eq!(
+            make_title_case_str("midnight river", &PlainEnglish, &FstDictionary::curated()),
+            "Midnight River",
+        );
+    }
+
+    #[test]
+    fn handles_a_quiet_room() {
+        assert_eq!(
+            make_title_case_str("a quiet room", &PlainEnglish, &FstDictionary::curated()),
+            "A Quiet Room",
+        );
+    }
+
+    #[test]
+    fn handles_broken_map() {
+        assert_eq!(
+            make_title_case_str("broken map", &PlainEnglish, &FstDictionary::curated()),
+            "Broken Map",
+        );
+    }
+
+    #[test]
+    fn handles_fire_in_autumn() {
+        assert_eq!(
+            make_title_case_str("fire in autumn", &PlainEnglish, &FstDictionary::curated()),
+            "Fire in Autumn",
+        );
+    }
+
+    #[test]
+    fn handles_hidden_path() {
+        assert_eq!(
+            make_title_case_str("the hidden path", &PlainEnglish, &FstDictionary::curated()),
+            "The Hidden Path",
+        );
+    }
+
+    #[test]
+    fn handles_under_blue_skies() {
+        assert_eq!(
+            make_title_case_str("under blue skies", &PlainEnglish, &FstDictionary::curated()),
+            "Under Blue Skies",
+        );
+    }
+
+    #[test]
+    fn handles_lost_and_found() {
+        assert_eq!(
+            make_title_case_str("lost and found", &PlainEnglish, &FstDictionary::curated()),
+            "Lost and Found",
+        );
+    }
+
+    #[test]
+    fn handles_silent_watcher() {
+        assert_eq!(
+            make_title_case_str(
+                "the silent watcher",
+                &PlainEnglish,
+                &FstDictionary::curated()
+            ),
+            "The Silent Watcher",
+        );
+    }
+
+    #[test]
+    fn handles_winter_road() {
+        assert_eq!(
+            make_title_case_str("winter road", &PlainEnglish, &FstDictionary::curated()),
+            "Winter Road",
+        );
+    }
 }
--- a/harper-core/src/token_kind.rs
+++ b/harper-core/src/token_kind.rs
@@ -50,6 +50,7 @@ pub enum TokenKind {
    Unlintable,
    ParagraphBreak,
    Regexish,
+    HeadingStart,
 }

 impl TokenKind {
--- a/harper-core/src/token_string_ext.rs
+++ b/harper-core/src/token_string_ext.rs
@@ -88,6 +88,7 @@ pub trait TokenStringExt: private::Sealed {
    create_decl_for!(verb);
    create_decl_for!(word);
    create_decl_for!(word_like);
+    create_decl_for!(heading_start);

    fn iter_linking_verb_indices(&self) -> impl Iterator<Item = usize> + '_;
    fn iter_linking_verbs(&self) -> impl Iterator<Item = &Token> + '_;
@@ -106,6 +107,12 @@ pub trait TokenStringExt: private::Sealed {
    /// paragraphs in a document.
    fn iter_paragraphs(&self) -> impl Iterator<Item = &'_ [Token]> + '_;

+    /// Get an iterator over token slices that represent headings.
+    ///
+    /// A heading begins with a [`TokenKind::HeadingStart`] token and ends with
+    /// the next [`TokenKind::ParagraphBreak`].
+    fn iter_headings(&self) -> impl Iterator<Item = &'_ [Token]> + '_;
+
    /// Get an iterator over token slices that represent the individual
    /// sentences in a document.
    fn iter_sentences(&self) -> impl Iterator<Item = &'_ [Token]> + '_;
@@ -139,6 +146,7 @@ impl TokenStringExt for [Token] {
    create_fns_for!(verb);
    create_fns_for!(word_like);
    create_fns_for!(word);
+    create_fns_for!(heading_start);

    fn first_non_whitespace(&self) -> Option<&Token> {
        self.iter().find(|t| !t.kind.is_whitespace())
@@ -230,6 +238,17 @@ impl TokenStringExt for [Token] {
        first_pg.into_iter().chain(rest).chain(last_pg)
    }

+    fn iter_headings(&self) -> impl Iterator<Item = &'_ [Token]> + '_ {
+        self.iter_heading_start_indices().map(|start| {
+            let end = self[start..]
+                .iter()
+                .position(|t| t.kind.is_paragraph_break())
+                .unwrap_or(self[start..].len() - 1);
+
+            &self[start..=start + end]
+        })
+    }
+
    fn iter_sentences(&self) -> impl Iterator<Item = &'_ [Token]> + '_ {
        let first_sentence = self
            .iter_sentence_terminator_indices()
--- a/harper-core/tests/pos_tags.rs
+++ b/harper-core/tests/pos_tags.rs
@@ -302,6 +302,7 @@ fn format_tag(kind: &TokenKind) -> Cow<'static, str> {
        TokenKind::Unlintable => Cow::Borrowed("Unlintable"),
        TokenKind::Regexish => Cow::Borrowed("Regexish"),
        TokenKind::ParagraphBreak => Cow::Borrowed("ParagraphBreak"),
+        TokenKind::HeadingStart => Cow::Borrowed("HeadingStart"),
    }
 }

--- a/harper-core/tests/run_tests.rs
+++ b/harper-core/tests/run_tests.rs
@@ -92,6 +92,8 @@ create_test!(issue_1988.md, 0, Dialect::American);
 create_test!(issue_2054_clean.md, 0, Dialect::British);
 create_test!(issue_1873.md, 0, Dialect::British);
 create_test!(issue_2246.md, 0, Dialect::American);
+create_test!(title_case_errors.md, 2, Dialect::American);
+create_test!(title_case_clean.md, 0, Dialect::American);
 create_test!(issue_2233.md, 0, Dialect::American);
 create_test!(issue_2240.md, 0, Dialect::American);
 // It just matters that it is > 1
--- a/harper-core/tests/test_sources/title_case_clean.md
+++ b/harper-core/tests/test_sources/title_case_clean.md
@@ -0,0 +1,7 @@
+# Here, We Try to Test Our Title-Casing Feature
+
+It should only pay attention to headings.
+
+## Maybe It Works?
+
+There will be a similar file with the corrected headings.
--- a/harper-core/tests/test_sources/title_case_errors.md
+++ b/harper-core/tests/test_sources/title_case_errors.md
@@ -0,0 +1,7 @@
+# Here, we try to test our title-casing feature
+
+It should only pay attention to headings.
+
+## Maybe it works?
+
+There will be a similar file with the corrected headings.
--- a/harper-core/tests/test_sources/whack_bullets.md
+++ b/harper-core/tests/test_sources/whack_bullets.md
@@ -1,4 +1,4 @@
-# This is a big heading, with a lot of words
+# This Is a Big Heading, with a Lot of Words

 - New here's a list, this part doesn't have as many words
    - But this part does, it has so many words, more words than you could ever dream of
--- a/harper-core/tests/text/linters/Alice's
+++ b/harper-core/tests/text/linters/Alice's
@@ -985,6 +985,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     558 | ## CHAPTER IV: The Rabbit Sends in a Little Bill
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## CHAPTER IV: The Rabbit Sends in a little Bill”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
     564 | wonder?” Alice guessed in a moment that it was looking for the fan and the pair
@@ -1417,6 +1426,15 @@ Message: |



+Lint:    Capitalization (127 priority)
+Message: |
+     796 | ## CHAPTER V: Advice from a Caterpillar
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## CHAPTER v: Advice from a Caterpillar”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
     822 | “Well, perhaps you haven’t found it so yet,” said Alice; “but when you have to
@@ -1639,6 +1657,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+    1059 | ## CHAPTER VI: Pig and Pepper
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## CHAPTER Vi: Pig and Pepper”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
    1061 | For a minute or two she stood looking at the house, and wondering what to do
--- a/harper-core/tests/text/linters/Computer
+++ b/harper-core/tests/text/linters/Computer
@@ -1,3 +1,12 @@
+Lint:    Capitalization (127 priority)
+Message: |
+       6 | # Computer science
+         | ^~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “# Computer Science”
+
+
+
 Lint:    Style (31 priority)
 Message: |
      27 | problem-solving, decision-making, environmental adaptation, planning and
@@ -197,6 +206,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     102 | ## Etymology and scope
+         | ^~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## Etymology and Scope”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
     104 | Although first proposed in 1956, the term "computer science" appears in a 1959
@@ -594,6 +612,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     178 | ### Epistemology of computer science
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Epistemology of Computer Science”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     181 | computer science is a discipline of science, mathematics, or engineering. Allen
@@ -682,6 +709,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     211 | ### Paradigms of computer science
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Paradigms of Computer Science”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     214 | separate paradigms in computer science. Peter Wegner argued that those paradigms
@@ -824,6 +860,24 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     243 | ### Theoretical computer science
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Theoretical Computer Science”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     250 | #### Theory of computation
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Theory of Computation”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     252 | According to Peter Denning, the fundamental question underlying computer science
@@ -855,6 +909,33 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     265 | #### Information and coding theory
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Information and Coding Theory”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     277 | #### Data structures and algorithms
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Data Structures and Algorithms”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     282 | #### Programming language theory and formal methods
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Programming Language Theory and Formal Methods”
+
+
+
 Lint:    Agreement (31 priority)
 Message: |
     286 | programming languages and their individual features. It falls within the
@@ -891,6 +972,33 @@ Message: |



+Lint:    Capitalization (127 priority)
+Message: |
+     308 | ### Applied computer science
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Applied Computer Science”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     310 | #### Computer graphics and visualization
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Computer Graphics and Visualization”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     318 | #### Image and sound processing
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Image and Sound Processing”
+
+
+
 Lint:    Style (31 priority)
 Message: |
     320 | Information can take the form of images, sound, video or other multimedia. Bits
@@ -920,6 +1028,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     330 | #### Computational science, finance and engineering
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Computational Science, Finance and Engineering”
+
+
+
 Lint:    Style (31 priority)
 Message: |
     330 | #### Computational science, finance and engineering
@@ -929,6 +1046,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     344 | #### Human–computer interaction
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Human–Computer Interaction”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     346 | Human–computer interaction (HCI) is the field of study and research concerned
@@ -952,6 +1078,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     352 | #### Software engineering
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Software Engineering”
+
+
+
 Lint:    Punctuation (31 priority)
 Message: |
     360 | maintenance. For example software testing, systems engineering, technical debt
@@ -961,6 +1096,33 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     363 | #### Artificial intelligence
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Artificial Intelligence”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     383 | ### Computer systems
+         | ^~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Computer Systems”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     385 | #### Computer architecture and microarchitecture
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Computer Architecture and Microarchitecture”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     393 | term "architecture" in computer literature can be traced to the work of Lyle R.
@@ -983,6 +1145,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     397 | #### Concurrent, parallel and distributed computing
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Concurrent, Parallel and Distributed Computing”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     401 | mathematical models have been developed for general concurrent computation
@@ -995,6 +1166,24 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     408 | #### Computer networks
+         | ^~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Computer Networks”
+
+
+
+Lint:    Capitalization (127 priority)
+Message: |
+     413 | #### Computer security and cryptography
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Computer Security and Cryptography”
+
+
+
 Lint:    WordChoice (127 priority)
 Message: |
     421 | Modern cryptography is the scientific study of problems relating to distributed
@@ -1005,6 +1194,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     427 | #### Databases and data mining
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Databases and Data Mining”
+
+
+
 Lint:    WordChoice (63 priority)
 Message: |
     432 | languages. Data mining is a process of discovering patterns in large data sets.
@@ -1149,6 +1347,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     471 | ## Programming paradigms
+         | ^~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## Programming Paradigms”
+
+
+
 Lint:    Punctuation (31 priority)
 Message: |
     490 |   the data fields of the object with which they are associated. Thus
--- a/harper-core/tests/text/linters/Difficult
+++ b/harper-core/tests/text/linters/Difficult
@@ -1,3 +1,12 @@
+Lint:    Capitalization (127 priority)
+Message: |
+       1 | # Difficult sentences
+         | ^~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “# Difficult Sentences”
+
+
+
 Lint:    Capitalization (31 priority)
 Message: |
      20 | at the bottom of the page; sitting at the table; at church; at sea
--- a/harper-core/tests/text/linters/Part-of-speech
+++ b/harper-core/tests/text/linters/Part-of-speech
@@ -1,3 +1,12 @@
+Lint:    Capitalization (127 priority)
+Message: |
+       6 | # Part-of-speech tagging
+         | ^~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “# Part-of-Speech Tagging”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
       8 | In corpus linguistics, part-of-speech tagging (POS tagging or PoS tagging or
@@ -71,6 +80,15 @@ Message: |



+Lint:    Capitalization (127 priority)
+Message: |
+      39 | ### Tag sets
+         | ^~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Tag Sets”
+
+
+
 Lint:    Spelling (127 priority)
 Message: |
      43 | However, there are clearly many more categories and sub-categories. For nouns,
@@ -286,6 +304,15 @@ Message: |



+Lint:    Capitalization (127 priority)
+Message: |
+     117 | ### Use of hidden Markov models
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Use of Hidden Markov Models”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     119 | In the mid-1980s, researchers in Europe began to use hidden Markov models (HMMs)
@@ -390,6 +417,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     157 | ### Dynamic programming methods
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “### Dynamic Programming Methods”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     159 | In 1987, Steven DeRose and Kenneth W. Church independently developed dynamic
@@ -499,6 +535,15 @@ Message: |



+Lint:    Capitalization (127 priority)
+Message: |
+     182 | #### Unsupervised taggers
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Unsupervised Taggers”
+
+
+
 Lint:    Spelling (127 priority)
 Message: |
     184 | The methods already discussed involve working from a pre-existing corpus to
@@ -509,6 +554,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     198 | #### Other taggers and methods
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “#### Other Taggers and Methods”
+
+
+
 Lint:    Spelling (63 priority)
 Message: |
     200 | Some current major algorithms for part-of-speech tagging include the Viterbi
--- a/harper-core/tests/text/linters/The
+++ b/harper-core/tests/text/linters/The
@@ -1,3 +1,12 @@
+Lint:    Capitalization (127 priority)
+Message: |
+       3 | # The Constitution Of The United States Of America
+         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “# The Constitution of the United States of America”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
       5 | **We the People** of the United States, in Order to form a more perfect Union,
@@ -1776,6 +1785,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+     677 | ## Article. VI.
+         | ^~~~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## Article. Vi.”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
     683 | This Constitution, and the Laws of the United States which shall be made in
--- a/harper-core/tests/text/linters/The
+++ b/harper-core/tests/text/linters/The
@@ -4438,6 +4438,15 @@ Suggest:



+Lint:    Capitalization (127 priority)
+Message: |
+    3003 | ## CHAPTER VI
+         | ^~~~~~~~~~~~~ Try to use title case in headings.
+Suggest:
+  - Replace with: “## CHAPTER Vi”
+
+
+
 Lint:    Readability (127 priority)
 Message: |
    3020 | short of being news. Contemporary legends such as the “underground pipe-line to
--- a/harper-core/tests/text/tagged/Alice's
+++ b/harper-core/tests/text/tagged/Alice's
@@ -1,5 +1,5 @@
-> Alice’s Adventures in        Wonderland
-# NSg$    NPl/V3     NPr/J/R/P NSg+
+>              Alice’s Adventures in        Wonderland
+# HeadingStart NSg$    NPl/V3     NPr/J/R/P NSg+
 >
 #
 > by      Lewis Carroll
@@ -10,8 +10,8 @@
 # D   NSg+       NSg     NSg+    #
 >
 #
-> CHAPTER I       : Down        the Rabbit  - Hole
-# NSg/VB+ ISg/#r+ . N🅪Sg/VB/J/P D   NSg/VB+ . NSg/VB+
+>              CHAPTER I       : Down        the Rabbit  - Hole
+# HeadingStart NSg/VB+ ISg/#r+ . N🅪Sg/VB/J/P D   NSg/VB+ . NSg/VB+
 >
 #
 > Alice was beginning to get    very tired of sitting  by      her     sister  on  the bank    , and
@@ -370,8 +370,8 @@
 # NSg/I/J/R/C ISg+ NPr/VBP/J P  N🅪Sg/VB . VB/C J/R  J/R  VP/J     NSg/VB/J/P D+  N🅪Sg/VB+ .
 >
 #
-> CHAPTER II : The Pool   of Tears
-# NSg/VB+ #r . D   NSg/VB P  NPl/V3+
+>              CHAPTER II : The Pool   of Tears
+# HeadingStart NSg/VB+ #r . D   NSg/VB P  NPl/V3+
 >
 #
 > “ Curiouser and  curiouser ! ” cried Alice ( she  was so          much         surprised , that         for   the
@@ -728,8 +728,8 @@
 # NSg/VB/J+ VPt  P  D+  NSg/VB+ .
 >
 #
-> CHAPTER III : A   Caucus  - Race    and  a    Long      Tale
-# NSg/VB+ #r  . D/P NSg/VB+ . N🅪Sg/VB VB/C D/P+ NPr/VB/J+ NSg/VB+
+>              CHAPTER III : A   Caucus  - Race    and  a   Long     Tale
+# HeadingStart NSg/VB+ #r  . D/P NSg/VB+ . N🅪Sg/VB VB/C D/P NPr/VB/J NSg/VB+
 >
 #
 > They were    indeed a   queer    - looking party     that          assembled on  the bank   — the birds  with
@@ -1114,8 +1114,8 @@
 # NSg/VB+ . VB/C VPt Nᴹ/Vg/J NSg/VB/J P  NSg/VB ISg/D$+ NSg/VB+ .
 >
 #
-> CHAPTER IV        : The Rabbit  Sends  in        a    Little      Bill
-# NSg/VB+ NSg/J/#r+ . D+  NSg/VB+ NPl/V3 NPr/J/R/P D/P+ NPr/I/J/Dq+ NPr/VB+
+>              CHAPTER IV        : The Rabbit  Sends  in        a   Little     Bill
+# HeadingStart NSg/VB+ NSg/J/#r+ . D   NSg/VB+ NPl/V3 NPr/J/R/P D/P NPr/I/J/Dq NPr/VB+
 >
 #
 > It       was the White       Rabbit , trotting slowly back     again , and  looking anxiously about
@@ -1590,8 +1590,8 @@
 # D   JS       NSg/VB P  ISg/D$+ NPr/C P  NSg/I/VB+ NSg/J/C .
 >
 #
-> CHAPTER V        : Advice from a   Caterpillar
-# NSg/VB+ NSg/P/#r . Nᴹ+    P    D/P NSg/VB
+>              CHAPTER V        : Advice from a   Caterpillar
+# HeadingStart NSg/VB+ NSg/P/#r . Nᴹ+    P    D/P NSg/VB
 >
 #
 > The Caterpillar and  Alice looked at    each other    for   some     time       in        silence : at    last
@@ -2116,8 +2116,8 @@
 # VB  VP      ISg+    N🅪Sg/VB/J/P P  NSg  NPl/V3+ NSg/VB/J/R .
 >
 #
-> CHAPTER VI     : Pig    and  Pepper
-# NSg/VB+ NPr/#r . NSg/VB VB/C N🅪Sg/VB+
+>              CHAPTER VI     : Pig    and  Pepper
+# HeadingStart NSg/VB+ NPr/#r . NSg/VB VB/C N🅪Sg/VB+
 >
 #
 > For   a    minute    or    two she  stood looking at    the house   , and  wondering what   to do
@@ -2706,8 +2706,8 @@
 # P     NSg/I/J/C/Dq . ISg/#r+ R      NSg/VB K   VPp/J/P P  NSg/VB D   NSg/VB R       . .
 >
 #
-> CHAPTER VII    : A   Mad      Tea      - Party
-# NSg/VB+ NSg/#r . D/P NSg/VB/J N🅪Sg/VB+ . NSg/VB/J+
+>              CHAPTER VII    : A   Mad      Tea      - Party
+# HeadingStart NSg/VB+ NSg/#r . D/P NSg/VB/J N🅪Sg/VB+ . NSg/VB/J+
 >
 #
 > There was a    table   set       out          under   a   tree    in        front    of the house   , and  the March   Hare
@@ -3334,8 +3334,8 @@
 # NPr/VB/J NSg/VB+ . NPl/V3+ VB/C D   NSg/VB/J NPl/V3    .
 >
 #
-> CHAPTER VIII : The Queen’s Croquet - Ground
-# NSg/VB+ #r   . D   NSg$    NSg/VB  . N🅪Sg/VB/J+
+>              CHAPTER VIII : The Queen’s Croquet - Ground
+# HeadingStart NSg/VB+ #r   . D   NSg$    NSg/VB  . N🅪Sg/VB/J+
 >
 #
 > A   large rose       - tree   stood near       the entrance of the garden    : the roses   growing on  it
@@ -3896,8 +3896,8 @@
 # NSg/VPt NSg/VB/J P  D   NSg/VB/J+ .
 >
 #
-> CHAPTER IX : The Mock     Turtle’s Story
-# NSg/VB+ #r . D   NSg/VB/J NSg$     NSg/VB+
+>              CHAPTER IX : The Mock     Turtle’s Story
+# HeadingStart NSg/VB+ #r . D   NSg/VB/J NSg$     NSg/VB+
 >
 #
 > “ You    can’t think  how   glad     I       am       to see    you    again , you    dear     old   thing ! ” said the
@@ -4486,8 +4486,8 @@
 # . NPr/VB ISg/D$+ NSg/I/J+  J/P   D   NPl/V3+ NSg/J/R/C . .
 >
 #
-> CHAPTER X         : The Lobster   Quadrille
-# NSg/VB+ NPr/J/#r+ . D+  NSg/VB/J+ NSg/VB/J
+>              CHAPTER X         : The Lobster   Quadrille
+# HeadingStart NSg/VB+ NPr/J/#r+ . D+  NSg/VB/J+ NSg/VB/J
 >
 #
 > The Mock      Turtle  sighed deeply , and  drew    the back     of one     flapper across his     eyes    .
@@ -5008,8 +5008,8 @@
 # . ?   . Nᴹ  P  D   NPr/I+ . NPr/I+ . N🅪Sg/Vg/J+ . NSg/J     . NSg/J     N🅪Sg/VB+ . .
 >
 #
-> CHAPTER XI     : Who    Stole   the Tarts  ?
-# NSg/VB+ NSg/#r . NPr/I+ NSg/VPt D   NPl/V3 .
+>              CHAPTER XI     : Who    Stole   the Tarts  ?
+# HeadingStart NSg/VB+ NSg/#r . NPr/I+ NSg/VPt D   NPl/V3 .
 >
 #
 > The King     and  Queen    of Hearts  were    seated on  their throne when    they arrived , with
@@ -5488,8 +5488,8 @@
 # NSg/P D   NSg/VB/J P  ISg/D$+ NSg/VB/J NPr/I/J/Dq+ NSg/VB+ . D+  NSg/VB+ . NPr+  . .
 >
 #
-> CHAPTER XII : Alice’s Evidence
-# NSg/VB+ #r  . NSg$    Nᴹ/VB+
+>              CHAPTER XII : Alice’s Evidence
+# HeadingStart NSg/VB+ #r  . NSg$    Nᴹ/VB+
 >
 #
 > “ Here    ! ” cried Alice , quite forgetting in        the flurry of the moment how   large she
--- a/harper-core/tests/text/tagged/Computer
+++ b/harper-core/tests/text/tagged/Computer
@@ -6,8 +6,8 @@
 # Unlintable Unlintable
 >            -->
 # Unlintable Unlintable
->            Computer science
-# Unlintable NSg/VB+  N🅪Sg/VB+
+>                         Computer science
+# Unlintable HeadingStart NSg/VB+  N🅪Sg/VB+
 >
 #
 > Computer science  is  the study  of computation , information , and  automation .
@@ -66,8 +66,8 @@
 # N🅪Sg        NPr/J/R/P NSg/VB+  N🅪Sg/VB+ .
 >
 #
-> History
-# N🅪Sg+
+>              History
+# HeadingStart N🅪Sg+
 >
 #
 > The earliest foundations of what   would become computer science  predate the
@@ -198,8 +198,8 @@
 # VB/J     NPl   P  NSg/VB+ NPr/J/R/P D$+   NSg/VB/J+ NPl/V3+ .
 >
 #
-> Etymology and  scope
-# N🅪Sg      VB/C NSg/VB+
+>              Etymology and  scope
+# HeadingStart N🅪Sg      VB/C NSg/VB+
 >
 #
 > Although first    proposed in        1956 , the term     " computer science  " appears in        a   1959
@@ -346,12 +346,12 @@
 # NSg/C NSg/R/C NSg/P  NSg/I/J/C/Dq Nᴹ/VB+   .
 >
 #
-> Philosophy
-# N🅪Sg/VB+
+>              Philosophy
+# HeadingStart N🅪Sg/VB+
 >
 #
-> Epistemology of computer science
-# Nᴹ           P  NSg/VB+  N🅪Sg/VB+
+>              Epistemology of computer science
+# HeadingStart Nᴹ           P  NSg/VB+  N🅪Sg/VB+
 >
 #
 > Despite  the word    science  in        its     name    , there is  debate   over    whether or    not
@@ -416,8 +416,8 @@
 # Nᴹ/Vg/J+    NPl/V3+   NSg/R J            J         NPl+    .
 >
 #
-> Paradigms of computer science
-# NPl       P  NSg/VB+  N🅪Sg/VB+
+>              Paradigms of computer science
+# HeadingStart NPl       P  NSg/VB+  N🅪Sg/VB+
 >
 #
 > A   number     of computer scientists have    argued for   the distinction of three
@@ -448,8 +448,8 @@
 # NSg/VB/J . VB   Nᴹ/Vg/J+  NPl+    .
 >
 #
-> Fields
-# NPrPl/V3+
+>              Fields
+# HeadingStart NPrPl/V3+
 >
 #
 > As    a    discipline , computer science  spans  a   range   of topics from theoretical
@@ -480,8 +480,8 @@
 # NSg         NSg/R N🅪Sg/Vg/J/C J         NPl   P  NSg/VB+  N🅪Sg/VB+ .
 >
 #
-> Theoretical computer science
-# J+          NSg/VB+  N🅪Sg/VB+
+>              Theoretical computer science
+# HeadingStart J+          NSg/VB+  N🅪Sg/VB+
 >
 #
 > Theoretical computer science  is  mathematical and  abstract in        spirit  , but     it
@@ -494,8 +494,8 @@
 # N🅪Sg/Vg/J+    . VB      NPr/I/J/R/Dq NSg/J     NPl           .
 >
 #
-> Theory of computation
-# N🅪Sg   P  NSg
+>              Theory of computation
+# HeadingStart N🅪Sg   P  NSg
 >
 #
 > According to Peter      Denning , the fundamental question underlying computer science
@@ -524,8 +524,8 @@
 # NSg/J   NPr/J/R/P D   N🅪Sg   P  NSg         .
 >
 #
-> Information and  coding   theory
-# Nᴹ          VB/C Nᴹ/Vg/J+ N🅪Sg+
+>              Information and  coding   theory
+# HeadingStart Nᴹ          VB/C Nᴹ/Vg/J+ N🅪Sg+
 >
 #
 > Information theory , closely related to probability and  statistics , is  related to
@@ -548,8 +548,8 @@
 # NSg/J     VB/C NSg/J+   N🅪Pl+ N🅪Sg+        NPl/V3+ .
 >
 #
-> Data  structures and  algorithms
-# N🅪Pl+ NPl/V3     VB/C NPl+
+>              Data  structures and  algorithms
+# HeadingStart N🅪Pl+ NPl/V3     VB/C NPl+
 >
 #
 > Data  structures and  algorithms are the studies of commonly used computational
@@ -558,8 +558,8 @@
 # NPl/V3  VB/C D$+   J+            N🅪Sg+      .
 >
 #
-> Programming language theory and  formal methods
-# Nᴹ/Vg/J+    N🅪Sg/VB+ N🅪Sg   VB/C NSg/J+ NPl/V3+
+>              Programming language theory and  formal methods
+# HeadingStart Nᴹ/Vg/J+    N🅪Sg/VB+ N🅪Sg   VB/C NSg/J  NPl/V3+
 >
 #
 > Programming language theory is  a   branch of computer science  that          deals  with the
@@ -610,12 +610,12 @@
 # NPl      NPr/J/R/P Nᴹ       VB/C Nᴹ+      NSg           VB/C N🅪Sg+        .
 >
 #
-> Applied computer science
-# VP/J    NSg/VB+  N🅪Sg/VB+
+>              Applied computer science
+# HeadingStart VP/J    NSg/VB+  N🅪Sg/VB+
 >
 #
-> Computer graphics and  visualization
-# NSg/VB+  NPl      VB/C NSg+
+>              Computer graphics and  visualization
+# HeadingStart NSg/VB+  NPl      VB/C NSg+
 >
 #
 > Computer graphics is  the study  of digital visual contents and  involves the
@@ -630,8 +630,8 @@
 # VB/C N🅪Sg/VB+ NPl/V3+ .
 >
 #
-> Image   and  sound      processing
-# N🅪Sg/VB VB/C N🅪Sg/VB/J+ Nᴹ/Vg/J+
+>              Image   and  sound      processing
+# HeadingStart N🅪Sg/VB VB/C N🅪Sg/VB/J+ Nᴹ/Vg/J+
 >
 #
 > Information can     take   the form    of images  , sound      , video    or    other    multimedia . Bits
@@ -654,8 +654,8 @@
 # NSg/I/J P  D   VP/J     NPl      NPr/J/R/P J+          NSg/VB+  N🅪Sg/VB+ .
 >
 #
-> Computational science  , finance and  engineering
-# J             N🅪Sg/VB+ . N🅪Sg/VB VB/C Nᴹ/Vg/J+
+>              Computational science  , finance and  engineering
+# HeadingStart J             N🅪Sg/VB+ . N🅪Sg/VB VB/C Nᴹ/Vg/J+
 >
 #
 > Scientific computing ( or    computational science  ) is  the field  of study   concerned
@@ -682,8 +682,8 @@
 # NPl/V3   .
 >
 #
-> Human    – computer interaction
-# NSg/VB/J . NSg/VB+  N🅪Sg+
+>              Human    – computer interaction
+# HeadingStart NSg/VB/J . NSg/VB+  N🅪Sg+
 >
 #
 > Human    – computer interaction ( HCI ) is  the field  of study  and  research concerned
@@ -698,8 +698,8 @@
 # NSg      P    NPl/V3+   .
 >
 #
-> Software engineering
-# Nᴹ+      Nᴹ/Vg/J+
+>              Software engineering
+# HeadingStart Nᴹ+      Nᴹ/Vg/J+
 >
 #
 > Software engineering is  the study  of designing , implementing , and  modifying the
@@ -720,8 +720,8 @@
 # VB/C Nᴹ+      N🅪Sg+       NPl/V3+   .
 >
 #
-> Artificial intelligence
-# J+         N🅪Sg+
+>              Artificial intelligence
+# HeadingStart J+         N🅪Sg+
 >
 #
 > Artificial intelligence ( AI      ) aims   to or    is  required to synthesize
@@ -760,12 +760,12 @@
 # N🅪Pl+ .
 >
 #
-> Computer systems
-# NSg/VB+  NPl+
+>              Computer systems
+# HeadingStart NSg/VB+  NPl+
 >
 #
-> Computer architecture and  microarchitecture
-# NSg/VB+  N🅪Sg+        VB/C NSg
+>              Computer architecture and  microarchitecture
+# HeadingStart NSg/VB+  N🅪Sg+        VB/C NSg
 >
 #
 > Computer architecture , or    digital computer organization , is  the conceptual
@@ -788,8 +788,8 @@
 # NSg+       NPr/J/R/P NSg$  NSg/VB/J+ Nᴹ/VB+   NSg/VB/J+ NPr/J/R/P #    .
 >
 #
-> Concurrent , parallel and  distributed computing
-# NSg/J      . NSg/VB/J VB/C VP/J        Nᴹ/Vg/J+
+>              Concurrent , parallel and  distributed computing
+# HeadingStart NSg/J      . NSg/VB/J VB/C VP/J        Nᴹ/Vg/J+
 >
 #
 > Concurrency is  a   property of systems in        which several computations are executing
@@ -810,8 +810,8 @@
 # VP/J      P  VB      NSg/VB/J+ NPl/V3+ .
 >
 #
-> Computer networks
-# NSg/VB+  NPl/V3+
+>              Computer networks
+# HeadingStart NSg/VB+  NPl/V3+
 >
 #
 > This   branch of computer science  aims   to manage networks between computers
@@ -820,8 +820,8 @@
 # J         .
 >
 #
-> Computer security and  cryptography
-# NSg/VB+  Nᴹ+      VB/C Nᴹ
+>              Computer security and  cryptography
+# HeadingStart NSg/VB+  Nᴹ+      VB/C Nᴹ
 >
 #
 > Computer security is  a   branch of computer technology with the objective of
@@ -848,8 +848,8 @@
 # VP/J    NPl/V3   .
 >
 #
-> Databases and  data  mining
-# NPl/V3    VB/C N🅪Pl+ Nᴹ/Vg/J+
+>              Databases and  data  mining
+# HeadingStart NPl/V3    VB/C N🅪Pl+ Nᴹ/Vg/J+
 >
 #
 > A    database is  intended to organize , store   , and  retrieve large amounts of data
@@ -862,8 +862,8 @@
 # NPl/V3+   . N🅪Pl+ Nᴹ/Vg/J+ VL3 D/P NSg/VB  P  Nᴹ/Vg/J     NPl/V3+  NPr/J/R/P NSg/J N🅪Pl+ NPl/V3 .
 >
 #
-> Discoveries
-# NPl+
+>              Discoveries
+# HeadingStart NPl+
 >
 #
 > The philosopher of computing Bill    Rapaport noted three Great Insights of
@@ -976,8 +976,8 @@
 #
 >
 #
-> Programming paradigms
-# Nᴹ/Vg/J+    NPl+
+>              Programming paradigms
+# HeadingStart Nᴹ/Vg/J+    NPl+
 >
 #
 > Programming languages can     be      used to accomplish different tasks   in        different
@@ -1044,8 +1044,8 @@
 # D/P N🅪Sg/VB P  NSg/VB+ C/P  P  NSg/J+    NPl+         .
 >
 #
-> Research
-# Nᴹ/VB+
+>              Research
+# HeadingStart Nᴹ/VB+
 >
 #
 > Conferences are important events for   computer science  research . During these
--- a/harper-core/tests/text/tagged/Difficult
+++ b/harper-core/tests/text/tagged/Difficult
@@ -1,5 +1,5 @@
-> Difficult sentences
-# VB/J+     NPl/V3+
+>              Difficult sentences
+# HeadingStart VB/J+     NPl/V3+
 >
 #
 > A   collection of difficult sentences to test   Harper's ability to correctly tag     unusual / uncommon but     correct  sentences .
@@ -14,8 +14,8 @@
 # NSg/I/J/R/Dq NSg/VB+ NPl/V3+   VB  VPp/J P    Url                         NSg/VB+ . NSg/VB/#r+ NSg/J/P . NPr/VB/J+ #   .
 >
 #
-> A
-# D/P
+>              A
+# HeadingStart D/P
 >
 #
 > With one      attack    , he       was torn a   pieces .
@@ -24,12 +24,12 @@
 # ISg/#r+ NSg/VB D$+ NPl+  R     D/P+ NPr🅪Sg+ .
 >
 #
-> At
-# NSg/P
+>              At
+# HeadingStart NSg/P
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > Caesar was at    Rome ; a   climate  treaty  was signed at    Kyoto in        1997 .
@@ -68,28 +68,28 @@
 # ISg+ VL3 NSg/P NPl   VB/C NPl    P    ISg+ .
 >
 #
-> Noun
-# NSg/VB+
+>              Noun
+# HeadingStart NSg/VB+
 >
 #
 > The at    sign    .
 # D   NSg/P NSg/VB+ .
 >
 #
-> Verb
-# NSg/VB+
+>              Verb
+# HeadingStart NSg/VB+
 >
 #
 > ( In        online chats   : ) Don't @ me       ! Don't at    me       !
 # . NPr/J/R/P VB/J+  NPl/V3+ . . VB    . NPr/ISg+ . VB    NSg/P NPr/ISg+ .
 >
 #
-> By
-# NSg/J/P
+>              By
+# HeadingStart NSg/J/P
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > The mailbox is  by      the bus     stop   .
@@ -176,8 +176,8 @@
 # NSg/J/P ?      . +    NSg/J     . . P    . P     .
 >
 #
-> Adverb
-# NSg/VB+
+>              Adverb
+# HeadingStart NSg/VB+
 >
 #
 > I       watched the parade  as    it       passed by      .
@@ -192,8 +192,8 @@
 # D+  NPl+  VB/J  NSg/I/J/R/Dq N🅪Sg/VB/J+ P     NSg/VB+ Nᴹ/Vg/J NPl/V3+ NSg/J/P R/C/P N🅪Sg/VB VB/C N🅪Sg/VB+ .
 >
 #
-> Adjective
-# NSg/VB/J+
+>              Adjective
+# HeadingStart NSg/VB/J+
 >
 #
 > a   by      path    ; a   by      room       ( Out          of the way    , off        to one      side      . )
@@ -202,20 +202,20 @@
 # NSg/J/P NSg/VB . D/P NSg/J/P NSg/VB . NSg/J+     . NSg/J      . .
 >
 #
-> For
-# R/C/P
+>              For
+# HeadingStart R/C/P
 >
 #
-> Conjunction
-# NSg/VB+
+>              Conjunction
+# HeadingStart NSg/VB+
 >
 #
 > I       had to stay     with my  wicked stepmother , for   I       had nowhere else    to go       .
 # ISg/#r+ VB  P  NSg/VB/J P    D$+ VP/J   NSg        . R/C/P ISg/#r+ VB  NSg/J   NSg/J/C P  NSg/VB/J .
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > The astronauts headed for   the moon    .
@@ -320,8 +320,8 @@
 # P  NSg/VB  R/C/P NSg$+ NSg+        .
 >
 #
-> From
-# P
+>              From
+# HeadingStart P
 >
 #
 > Paul is  from New    Zealand .
@@ -364,12 +364,12 @@
 # NPr/ISg+ NPl/V3 NPr/VB/J P    NSg/VB/J/R .
 >
 #
-> In
-# NPr/J/R/P
+>              In
+# HeadingStart NPr/J/R/P
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > Who    lives in        a   pineapple under   the sea  ?
@@ -450,16 +450,16 @@
 # NSg/J+   NPl/V3+ VXB    NSg/VXB NSg/J  NPr/J/R/P N🅪Sg/I/VB+ . NSg/C/P NSg/R/C VP/J    .
 >
 #
-> Verb
-# NSg/VB+
+>              Verb
+# HeadingStart NSg/VB+
 >
 #
 > He       that          ears    my  land       spares my  team    and  gives  me       leave  to in        the crop    .
 # NPr/ISg+ NSg/I/C/Ddem+ NPl/V3+ D$+ NPr🅪Sg/VB+ NPl/V3 D$+ NSg/VB+ VB/C NPl/V3 NPr/ISg+ NSg/VB P  NPr/J/R/P D   NSg/VB+ .
 >
 #
-> Adverb
-# NSg/VB+
+>              Adverb
+# HeadingStart NSg/VB+
 >
 #
 > Suddenly a    strange   man       walked in        .
@@ -478,16 +478,16 @@
 # D   NSg/VB NSg/VB/J VB     VBPp   Vg/J        #  NPl/V3+ NPr/J/R/P .
 >
 #
-> Noun
-# NSg/VB+
+>              Noun
+# HeadingStart NSg/VB+
 >
 #
 > His     parents got him  an  in        with the company  .
 # ISg/D$+ NPl/V3+ VP  ISg+ D/P NPr/J/R/P P    D+  N🅪Sg/VB+ .
 >
 #
-> Adjective
-# NSg/VB/J+
+>              Adjective
+# HeadingStart NSg/VB/J+
 >
 #
 > Is  Mr   . Smith   in        ?
@@ -522,8 +522,8 @@
 # ISg/#r+ VPt #   NPl     NPr/J/R/P NSg/I/C D+  N🅪Sg/VB/J+ VP/J    .
 >
 #
-> Unit
-# NSg+
+>              Unit
+# HeadingStart NSg+
 >
 #
 > The glass      is  8 inches  .
@@ -532,8 +532,8 @@
 # D+  NPr🅪Sg/VB+ VL3 # NPr/J/R/P .
 >
 #
-> Of
-# P
+>              Of
+# HeadingStart P
 >
 #
 > Take   the chicken    out          of the freezer .
@@ -582,12 +582,12 @@
 # P     D/P NSg/VB/J P  NSg+  NPl+  . D+  NSg/VB/J+ R       VPt  NSg/VB/J/P .
 >
 #
-> On
-# J/P
+>              On
+# HeadingStart J/P
 >
 #
-> Adjective
-# NSg/VB/J+
+>              Adjective
+# HeadingStart NSg/VB/J+
 >
 #
 > All           the lights  are on  , so          they must   be      home      .
@@ -624,8 +624,8 @@
 # NPr/ISg+ R      V3  P  NSg/VXB J/P . +    NSg/I/J/R/C Nᴹ/Vg/J    .
 >
 #
-> Adverb
-# NSg/VB+
+>              Adverb
+# HeadingStart NSg/VB+
 >
 #
 > turn   the television on
@@ -648,8 +648,8 @@
 # NSg+ NPl+  J/P . NSg/I/J+ VB  VP/J    NPr/J/R/P D+  NSg+    .
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > A   vase   of flowers   stood on  the table   .
@@ -768,20 +768,20 @@
 # VB     VB    NPr/VB J/P ISg/D$+ VB/C NSg/VB ISg/D$+ NPr/J/R/P N🅪Sg/VB+ .
 >
 #
-> Verb
-# NSg/VB+
+>              Verb
+# HeadingStart NSg/VB+
 >
 #
 > Can     you    on  the light      ? ( switch    on  )
 # NPr/VXB ISgPl+ J/P D+  N🅪Sg/VB/J+ . . NSg/VB/J+ J/P .
 >
 #
-> To
-# P
+>              To
+# HeadingStart P
 >
 #
-> Particle
-# NSg+
+>              Particle
+# HeadingStart NSg+
 >
 #
 > I       want   to leave  .
@@ -804,8 +804,8 @@
 # ISg/#r+ NSg/VPt P  D+  NPl/V3+ P  NSg/VB I/J/R/Dq+ N🅪Sg/VB+ .
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > She  looked to the heavens .
@@ -852,20 +852,20 @@
 # NSg$   D+  N🅪Sg/VB/J+ . . +    NSg/VB/J+ P  NSg  NPr/J/R/P D+  N🅪Sg+     . NPr/C # . #  NSg/VB+ . .
 >
 #
-> Adverb
-# NSg/VB+
+>              Adverb
+# HeadingStart NSg/VB+
 >
 #
 > Please push   the door    to . ( close    )
 # VB     NSg/VB D+  NSg/VB+ P  . . NSg/VB/J .
 >
 #
-> With
-# P
+>              With
+# HeadingStart P
 >
 #
-> Preposition
-# NSg/VB
+>              Preposition
+# HeadingStart NSg/VB
 >
 #
 > He       picked a   fight  with the class      bully     .
@@ -930,8 +930,8 @@
 # NSg/I/C/Ddem+ VPt D/P NPr/VB P  VB      . VB  ISgPl+ NSg/VB/J P    NPr/ISg+ .
 >
 #
-> Adverb
-# NSg/VB+
+>              Adverb
+# HeadingStart NSg/VB+
 >
 #
 > Do  you    want   to come       with ?
--- a/harper-core/tests/text/tagged/Part-of-speech
+++ b/harper-core/tests/text/tagged/Part-of-speech
@@ -6,8 +6,8 @@
 # Unlintable Unlintable
 >            -->
 # Unlintable Unlintable
->            Part      - of - speech   tagging
-# Unlintable NSg/VB/J+ . P  . N🅪Sg/VB+ NSg/Vg
+>                         Part      - of - speech   tagging
+# Unlintable HeadingStart NSg/VB/J+ . P  . N🅪Sg/VB+ NSg/Vg
 >
 #
 > In        corpus linguistics , part      - of - speech   tagging ( POS  tagging or    PoS  tagging or
@@ -36,8 +36,8 @@
 # NSg/VB/J VB/C NSg/I/J/R/Dq R      VP/J NPr🅪Sg/VB/J+ NSg+ . NPl     . NPl/V3  NSg/VB+ . VP/J  NPl+       .
 >
 #
-> Principle
-# N🅪Sg/VB+
+>              Principle
+# HeadingStart N🅪Sg/VB+
 >
 #
 > Part      - of - speech   tagging is  harder than just having  a   list   of words   and  their
@@ -72,8 +72,8 @@
 # J          NSg/VB+ . R        . . .
 >
 #
-> Tag     sets
-# NSg/VB+ NPl/V3
+>              Tag     sets
+# HeadingStart NSg/VB+ NPl/V3
 >
 #
 > Schools commonly teach  that         there are 9 parts  of speech  in        English     : noun    , verb    ,
@@ -156,12 +156,12 @@
 # J/P D   N🅪Sg/VB+ NSg/P NSg/VB+ . NSg/J     NSg/Vg  VL3 NSg/JC J/P NSg/JC  NSg/VB+ . NPl/V3 .
 >
 #
-> History
-# N🅪Sg+
+>              History
+# HeadingStart N🅪Sg+
 >
 #
-> The Brown        Corpus
-# D+  NPr🅪Sg/VB/J+ NSg+
+>              The Brown       Corpus
+# HeadingStart D+  NPr🅪Sg/VB/J NSg+
 >
 #
 > Research on  part      - of - speech   tagging has been    closely tied to corpus linguistics .
@@ -228,8 +228,8 @@
 # NPl+          NSg/VB NSg/VXB VP/J       R/C/P Dq+  NSg/VB+ .
 >
 #
-> Use     of hidden Markov models
-# N🅪Sg/VB P  VB/J   NPr    NPl/V3+
+>              Use     of hidden Markov models
+# HeadingStart N🅪Sg/VB P  VB/J   NPr    NPl/V3+
 >
 #
 > In        the mid      - 1980s , researchers in        Europe began to use     hidden Markov models  ( HMMs )
@@ -308,8 +308,8 @@
 # NSg       .
 >
 #
-> Dynamic programming methods
-# NSg/J+  Nᴹ/Vg/J+    NPl/V3+
+>              Dynamic programming methods
+# HeadingStart NSg/J+  Nᴹ/Vg/J+    NPl/V3+
 >
 #
 > In        1987 , Steven DeRose and  Kenneth W. Church     independently developed dynamic
@@ -358,8 +358,8 @@
 # NSg/VB/J+ . P  . N🅪Sg/VB+ NSg+       .
 >
 #
-> Unsupervised taggers
-# VB/J         NPl
+>              Unsupervised taggers
+# HeadingStart VB/J         NPl
 >
 #
 > The methods already discussed involve working from a    pre       - existing corpus to
@@ -390,8 +390,8 @@
 # J      NPl/V3+    .
 >
 #
-> Other    taggers and  methods
-# NSg/VB/J NPl     VB/C NPl/V3+
+>              Other    taggers and  methods
+# HeadingStart NSg/VB/J NPl     VB/C NPl/V3+
 >
 #
 > Some     current major    algorithms for   part      - of - speech   tagging include the Viterbi
--- a/harper-core/tests/text/tagged/Spell.US.md
+++ b/harper-core/tests/text/tagged/Spell.US.md
@@ -1,5 +1,5 @@
-> Spell
-# NSg/VB
+>              Spell
+# HeadingStart NSg/VB
 >
 #
 > This    document contains a   list   of words   spelled correctly in        some     dialects of English      , but     not     American English      . This    is  designed to test   the spelling suggestions we   give   for   such   mistakes .
@@ -10,8 +10,8 @@
 # P  VB      I/Ddem+ . D   NSg      P  I/Ddem NSg/VB+ V3       Unlintable . I/C+  NPr/VXB NPr/VB D   NSg/VB+  NSg       P  N🅪Sg/VB D   NPr/J    NSg+    . NPr/VB/J/R C/P  Nᴹ/Vg/J P  N🅪Sg/VB D/P R             VP/J     NSg+    .
 >
 #
-> Words
-# NPl/V3+
+>              Words
+# HeadingStart NPl/V3+
 >
 #
 >
--- a/harper-core/tests/text/tagged/Spell.md
+++ b/harper-core/tests/text/tagged/Spell.md
@@ -1,13 +1,13 @@
-> Spell
-# NSg/VB
+>              Spell
+# HeadingStart NSg/VB
 >
 #
 > This    document contains example sentences with misspelled words   that          we   want   to test   the spell  checker on  .
 # I/Ddem+ NSg/VB+  V3       NSg/VB+ NPl/V3+   P    VP/J       NPl/V3+ NSg/I/C/Ddem+ IPl+ NSg/VB P  NSg/VB D   NSg/VB NSg/VB  J/P .
 >
 #
-> Example Sentences
-# NSg/VB+ NPl/V3+
+>              Example Sentences
+# HeadingStart NSg/VB+ NPl/V3+
 >
 #
 > My  favourite      color         is  blu .
--- a/harper-core/tests/text/tagged/Swear.md
+++ b/harper-core/tests/text/tagged/Swear.md
@@ -1,13 +1,13 @@
-> Swears
-# NPl/V3
+>              Swears
+# HeadingStart NPl/V3
 >
 #
 > This    documents tests   that         different forms   / variations of swears are tagged as    such  .
 # I/Ddem+ NPl/V3+   NPl/V3+ NSg/I/C/Ddem NSg/J+    NPl/V3+ . NPl        P  NPl/V3 VB  VP/J   NSg/R NSg/I .
 >
 #
-> Examples
-# NPl/V3+
+>              Examples
+# HeadingStart NPl/V3+
 >
 #
 > One      turd      , two turds    .
--- a/harper-core/tests/text/tagged/The
+++ b/harper-core/tests/text/tagged/The
@@ -1,7 +1,7 @@
 > <!-- source: https://github.com/JesseKPhillips/USA-Constitution/blob/4cfdd130709fa7e8db998383b6917ba33b402ec6/Constitution.md -->
 # Unlintable
->            The Constitution Of The United States    Of America
-# Unlintable D   NPr+         P  D   VP/J   NPrPl/V3+ P  NPr+
+>                         The Constitution Of The United States   Of America
+# Unlintable HeadingStart D   NPr+         P  D   VP/J   NPrPl/V3 P  NPr+
 >
 #
 > We   the People of the United States    , in        Order    to form    a   more         perfect   Union     ,
@@ -16,12 +16,12 @@
 # NPrPl/V3 P  NPr+    .
 >
 #
-> Article . I.
-# NSg/VB+ . ?
+>              Article . I.
+# HeadingStart NSg/VB+ . ?
 >
 #
-> Section . 1 .
-# NSg/VB+ . # .
+>              Section . 1 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > All           legislative Powers    herein granted shall be      vested in        a
@@ -66,8 +66,8 @@
 # NPl+       VXB   NSg/J/R/C NSg/VB .
 >
 #
-> Section . 2 .
-# NSg/VB+ . # .
+>              Section . 2 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The House  of Representatives shall be      composed of Members
@@ -144,8 +144,8 @@
 # VXB   NSg/VXB D   NSg/VB/J N🅪Sg/VB/J+ P  N🅪Sg        .
 >
 #
-> Section . 3 .
-# NSg/VB+ . # .
+>              Section . 3 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The Senate of the United States    shall be      composed of two
@@ -226,8 +226,8 @@
 # N🅪Sg/VB .
 >
 #
-> Section . 4 .
-# NSg/VB+ . # .
+>              Section . 4 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The Times   , Places  and  Manner of holding Elections for   Senators
@@ -248,8 +248,8 @@
 # NSg/J     NPr🅪Sg+ .
 >
 #
-> Section . 5 .
-# NSg/VB+ . # .
+>              Section . 5 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > Each House   shall be      the Judge  of the Elections , Returns and
@@ -288,8 +288,8 @@
 # NPr/J/R/P I/C+  D   NSg NPl/V3+ VXB   NSg/VXB NSg/Vg/J .
 >
 #
-> Section . 6 .
-# NSg/VB+ . # .
+>              Section . 6 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The Senators and  Representatives shall receive a   Compensation
@@ -326,8 +326,8 @@
 # NSg/VXB VP/J       .
 >
 #
-> Section . 7 .
-# NSg/VB+ . # .
+>              Section . 7 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > All          Bills   for   raising Revenue shall originate in        the House  of
@@ -384,8 +384,8 @@
 # P  D   NPl/V3 VB/C NPl+        VP/J       NPr/J/R/P D   NPr🅪Sg/VB P  D/P NPr/VB+ .
 >
 #
-> Section . 8 .
-# NSg/VB+ . # .
+>              Section . 8 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The Congress shall have    Power      To lay      and  collect  Taxes   , Duties ,
@@ -582,8 +582,8 @@
 #
 >
 #
-> Section . 9 .
-# NSg/VB+ . # .
+>              Section . 9 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The Migration or    Importation of such  Persons as    any    of the
@@ -662,8 +662,8 @@
 # N🅪Sg/VB NPr/C NSg/VB/J N🅪Sg/VB+ .
 >
 #
-> Section . 10 .
-# NSg/VB+ . #  .
+>              Section . 10 .
+# HeadingStart NSg/VB+ . #  .
 >
 #
 > No        State    shall enter  into any    Treaty  , Alliance , or
@@ -702,12 +702,12 @@
 # VP/J    . NPr/C NPr/J/R/P NSg/I J        N🅪Sg/VB/JC+ NSg/R NPr/VXB NSg/R/C VB    P  NSg/VB/J+ .
 >
 #
-> Article . II .
-# NSg/VB+ . #r .
+>              Article . II .
+# HeadingStart NSg/VB+ . #r .
 >
 #
-> Section . 1 .
-# NSg/VB+ . # .
+>              Section . 1 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The executive Power      shall be      vested in        a   President of the
@@ -732,8 +732,8 @@
 # NPrPl/V3+ . VXB   NSg/VXB VP/J      D/P NSg     .
 >
 #
-> SubSection . 1 .
-# NSg/VB+    . # .
+>              SubSection . 1 .
+# HeadingStart NSg/VB+    . # .
 >
 #
 > The Electors shall meet     in        their respective states    , and  vote
@@ -828,8 +828,8 @@
 # VP/J   NPrPl/V3+ .
 >
 #
-> SubSection . 2
-# NSg/VB+    . #
+>              SubSection . 2
+# HeadingStart NSg/VB+    . #
 >
 #
 > No       Person  except a    natural born      Citizen , or    a   Citizen of the
@@ -864,8 +864,8 @@
 # Nᴹ/Vg/J NSg/R NSg/VB+   VB/P   D   NSg/VB/J  P  NSg/I+ NSg/VB/J+ .
 >
 #
-> SubSection 3 .
-# NSg/VB+    # .
+>              SubSection 3 .
+# HeadingStart NSg/VB+    # .
 >
 #
 > In        case      of the removal of the President from office  or    of his
@@ -942,8 +942,8 @@
 # VB/C NPl    P  ISg/D$+ NSg/VB+ .
 >
 #
-> SubSection 4 .
-# NSg/VB+    # .
+>              SubSection 4 .
+# HeadingStart NSg/VB+    # .
 >
 #
 > The President shall , at    stated Times   , receive for   his
@@ -970,8 +970,8 @@
 # NPrPl/V3+ . .
 >
 #
-> SubSection 5 .
-# NSg/VB+    # .
+>              SubSection 5 .
+# HeadingStart NSg/VB+    # .
 >
 #
 > The District  constituting the seat   of Government of the
@@ -998,8 +998,8 @@
 # NPr+         .
 >
 #
-> Section . 2 .
-# NSg/VB+ . # .
+>              Section . 2 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The President shall be      Commander in        Chief    of the Army and  Navy
@@ -1054,8 +1054,8 @@
 # N🅪Sg/VB+ .
 >
 #
-> Section . 3 .
-# NSg/VB+ . # .
+>              Section . 3 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > He       shall from time       to time      give   to the Congress Information of
@@ -1076,8 +1076,8 @@
 # N🅪Sg/VB    NSg/I/J/C/Dq D   NPl/V3   P  D   VP/J   NPrPl/V3+ .
 >
 #
-> Section . 4 .
-# NSg/VB+ . # .
+>              Section . 4 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The President , Vice        President and  all          civil Officers of the
@@ -1088,12 +1088,12 @@
 # P  . NSg     . Nᴹ      . NPr/C NSg/VB/J NSg/VB/J/R NPl/V3+ VB/C NPl          .
 >
 #
-> Article . III .
-# NSg/VB+ . #r  .
+>              Article . III .
+# HeadingStart NSg/VB+ . #r  .
 >
 #
-> Section . 1 .
-# NSg/VB+ . # .
+>              Section . 1 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The judicial Power     of the United States    , shall be      vested in
@@ -1110,8 +1110,8 @@
 # VB/P   D$+   NSg         NPr/J/R/P NSg/VB+ .
 >
 #
-> Section . 2 .
-# NSg/VB+ . # .
+>              Section . 2 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The judicial Power      shall extend to all           Cases   , in        Law     and
@@ -1154,8 +1154,8 @@
 # N🅪Sg/VB NPr/C NPl/V3+ NSg/R D   NPr/VB+  NPr/VXB NSg/J/P N🅪Sg/VB+ NSg/VXB VP/J     .
 >
 #
-> Section . 3 .
-# NSg/VB+ . # .
+>              Section . 3 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > Treason against the United States    , shall consist only  in
@@ -1176,8 +1176,8 @@
 # VB/P   D   N🅪Sg/VB P  D   NSg/VB+ VP/J      .
 >
 #
-> Section . 4 .
-# NSg/VB+ . # .
+>              Section . 4 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The right    of the people  to be      secure in        their persons , houses  ,
@@ -1242,12 +1242,12 @@
 # VB/C NSg/J   NPl+        VP/J      .
 >
 #
-> Article . IV        .
-# NSg/VB+ . NSg/J/#r+ .
+>              Article . IV        .
+# HeadingStart NSg/VB+ . NSg/J/#r+ .
 >
 #
-> Section . 1 .
-# NSg/VB+ . # .
+>              Section . 1 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > Full     Faith and  Credit  shall be      given       in        each State    to the
@@ -1260,8 +1260,8 @@
 # VB/C NPl+        VXB   NSg/VXB VP/J   . VB/C D+  NSg/VB+ R       .
 >
 #
-> Section . 2 .
-# NSg/VB+ . # .
+>              Section . 2 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > All           persons born     or    naturalized in        the United States    , and
@@ -1314,8 +1314,8 @@
 # NSg/VB  NPr/C NPr🅪Sg/VB/Comm+ NPr/VXB NSg/VXB NSg/J .
 >
 #
-> Section . 3 .
-# NSg/VB+ . # .
+>              Section . 3 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > New    States    may     be      admitted by      the Congress into this    Union     ; but
@@ -1340,8 +1340,8 @@
 # I/R/Dq NPl/V3 P  D   VP/J   NPrPl/V3+ . NPr/C P  I/R/Dq NSg/J      N🅪Sg/VB+ .
 >
 #
-> Section . 4 .
-# NSg/VB+ . # .
+>              Section . 4 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The United States    shall guarantee to every State    in        this    Union
@@ -1354,8 +1354,8 @@
 # NSg+        NSg/VB NSg/VXB VP/J     . C/P     NSg/J    Nᴹ/VB+   .
 >
 #
-> Section . 5 .
-# NSg/VB+ . # .
+>              Section . 5 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The validity of the public  debt of the United States    ,
@@ -1374,8 +1374,8 @@
 # NSg/I NPl+  . NPl         VB/C NPl/V3+ VXB   NSg/VXB VB   NSg/J   VB/C NSg/VB/J+ .
 >
 #
-> Article . V.
-# NSg/VB+ . ?
+>              Article . V.
+# HeadingStart NSg/VB+ . ?
 >
 #
 > The Congress , whenever two thirds of both   Houses  shall deem   it       necessary , shall
@@ -1402,8 +1402,8 @@
 # C/P     ISg/D$+ N🅪Sg/VB . VXB   NSg/VXB VP/J     P  ISg/D$+ NSg/VB/J NSg+     NPr/J/R/P D   NPr+   .
 >
 #
-> Article . VI     .
-# NSg/VB+ . NPr/#r .
+>              Article . VI     .
+# HeadingStart NSg/VB+ . NPr/#r .
 >
 #
 > All           Debts contracted and  Engagements entered into , before the Adoption of this
@@ -1446,8 +1446,8 @@
 # NPr/VB/J P  D   NPl/VB+ P  NSg/VB VB/C NSg/VB/J+ NPl/V3+ . VXB   NSg/R/C NSg/VXB VP/J      .
 >
 #
-> Section . 1 .
-# NSg/VB+ . # .
+>              Section . 1 .
+# HeadingStart NSg/VB+ . # .
 >
 #
 > The enumeration in        the Constitution , of certain rights  , shall
@@ -1464,8 +1464,8 @@
 # D   NPl/VB+ .
 >
 #
-> Article . VII    .
-# NSg/VB+ . NSg/#r .
+>              Article . VII    .
+# HeadingStart NSg/VB+ . NSg/#r .
 >
 #
 > The Ratification of the Conventions of nine States    , shall be      sufficient for   the
@@ -1498,12 +1498,12 @@
 # NSg/J   NPr/J/R/P NSg/VB  C       IPl+ NSg/VXB R        VP/J       D$+ NPl/V3+ .
 >
 #
-> Article . VIII .
-# NSg/VB+ . #r   .
+>              Article . VIII .
+# HeadingStart NSg/VB+ . #r   .
 >
 #
-> Section 1 .
-# NSg/VB+ # .
+>              Section 1 .
+# HeadingStart NSg/VB+ # .
 >
 #
 > The transportation or    importation into any    State    , Territory , or
--- a/harper-core/tests/text/tagged/The
+++ b/harper-core/tests/text/tagged/The
@@ -1,13 +1,13 @@
-> The Great Gatsby
-# D   NSg/J NPr
+>              The Great Gatsby
+# HeadingStart D   NSg/J NPr
 >
 #
 > BY      F. SCOTT FITZGERALD
 # NSg/J/P ?  NPr+  NPr
 >
 #
-> CHAPTER I
-# NSg/VB+ ISg/#r+
+>              CHAPTER I
+# HeadingStart NSg/VB+ ISg/#r+
 >
 #
 > In        my  younger and  more         vulnerable years my  father  gave me       some      advice that          I’ve
@@ -1296,8 +1296,8 @@
 # NPr/J/R/P D   VB/J    Nᴹ+      .
 >
 #
-> CHAPTER II
-# NSg/VB+ #r
+>              CHAPTER II
+# HeadingStart NSg/VB+ #r
 >
 #
 > About half         way   between West      Egg     and  New    York the motor     road    hastily joins  the
@@ -2310,8 +2310,8 @@
 # R       NSg/VB+ .
 >
 #
-> CHAPTER III
-# NSg/VB+ #r
+>              CHAPTER III
+# HeadingStart NSg/VB+ #r
 >
 #
 > There was music      from my  neighbor’s house   through the summer     nights  . In        his     blue
@@ -3656,8 +3656,8 @@
 # NSg/I/VB+ . ISg/#r+ NPr/VB/J NSg/I/J P  D+  NSg/I/Dq+ VB/JS+ NPl/VB+ NSg/I/C/Ddem+ ISg/#r+ NSg/VXB J/R  VPp/J .
 >
 #
-> CHAPTER IV
-# NSg/VB+ NSg/J/#r+
+>              CHAPTER IV
+# HeadingStart NSg/VB+ NSg/J/#r+
 >
 #
 > On  Sunday  morning    while      church     bells  rang in        the villages alongshore , the world
@@ -4944,8 +4944,8 @@
 # NSg/VB+ .
 >
 #
-> CHAPTER V
-# NSg/VB+ NSg/P/#r+
+>              CHAPTER V
+# HeadingStart NSg/VB+ NSg/P/#r+
 >
 #
 > When    I       came      home      to West      Egg      that          night    I       was afraid for   a    moment that          my  house
@@ -6002,8 +6002,8 @@
 # NSg/VB/J+ NPl/V3+ P    D+  N🅪Sg/VB+ . Nᴹ/Vg/J NSg/IPl+ R+    J        .
 >
 #
-> CHAPTER VI
-# NSg/VB+ NPr/#r
+>              CHAPTER VI
+# HeadingStart NSg/VB+ NPr/#r
 >
 #
 > About this    time       an  ambitious young    reporter from New    York arrived one     morning    at
@@ -6982,8 +6982,8 @@
 # VP/J       VPt ?              NSg/J   .
 >
 #
-> CHAPTER VII
-# NSg/VB+ NSg/#r
+>              CHAPTER VII
+# HeadingStart NSg/VB+ NSg/#r
 >
 #
 > It       was when    curiosity about Gatsby was at    its     highest that         the lights  in        his
@@ -9466,8 +9466,8 @@
 # VB/J VB/C NPr/VB/J ISg+ Nᴹ/Vg/J  R     NPr/J/R/P D+  N🅪Sg/VB+  . Nᴹ/Vg/J  NSg/J/P NSg/I/J+ .
 >
 #
-> CHAPTER VIII
-# NSg/VB+ #r
+>              CHAPTER VIII
+# HeadingStart NSg/VB+ #r
 >
 #
 > I       couldn’t sleep    all          night    ; a   fog      - horn    was groaning incessantly on  the Sound      ,
@@ -10448,8 +10448,8 @@
 # NSg$     NSg/VB+ D/P NPr/I/J/Dq NSg/J+ NSg/VB/J/P NPr/J/R/P D   NPr🅪Sg/VB+ . VB/C D   NPr/VB+   VPt NSg/VB/J .
 >
 #
-> CHAPTER IX
-# NSg/VB+ #r
+>              CHAPTER IX
+# HeadingStart NSg/VB+ #r
 >
 #
 > After two  years I       remember the rest   of that          day     , and  that         night   and  the next
--- a/harper-core/tests/text/tagged/this
+++ b/harper-core/tests/text/tagged/this
@@ -10,8 +10,8 @@
 # . I/Ddem . NPr/J/R/P NSg/J     NPl/V3   P    D/P NPr/VB P  NSg/VB+ NPl/V3+ .
 >
 #
-> Examples
-# NPl/V3+
+>              Examples
+# HeadingStart NPl/V3+
 >
 #
 > This   triangle is  nice  .
--- a/harper-wasm/src/lib.rs
+++ b/harper-wasm/src/lib.rs
@@ -7,7 +7,7 @@ use std::sync::Arc;
 use harper_core::DialectFlags;
 use harper_core::language_detection::is_doc_likely_english;
 use harper_core::linting::{LintGroup, Linter as _};
-use harper_core::parsers::{IsolateEnglish, Markdown, Parser, PlainEnglish};
+use harper_core::parsers::{IsolateEnglish, Markdown, OopsAllHeadings, Parser, PlainEnglish};
 use harper_core::remove_overlaps_map;
 use harper_core::{
    CharString, DictWordMetadata, Document, IgnoredLints, LintContext, Lrc, remove_overlaps,
@@ -253,11 +253,20 @@ impl Linter {
        ctx.default_hash()
    }

-    pub fn organized_lints(&mut self, text: String, language: Language) -> Vec<OrganizedGroup> {
+    pub fn organized_lints(
+        &mut self,
+        text: String,
+        language: Language,
+        all_headings: bool,
+    ) -> Vec<OrganizedGroup> {
        let source: Vec<_> = text.chars().collect();
        let source = Lrc::new(source);

-        let parser = language.create_parser();
+        let mut parser = language.create_parser();
+
+        if all_headings {
+            parser = Box::new(OopsAllHeadings::new(parser));
+        }

        let document = Document::new_from_vec(source.clone(), &parser, &self.dictionary);

@@ -292,11 +301,15 @@ impl Linter {
    }

    /// Perform the configured linting on the provided text.
-    pub fn lint(&mut self, text: String, language: Language) -> Vec<Lint> {
+    pub fn lint(&mut self, text: String, language: Language, all_headings: bool) -> Vec<Lint> {
        let source: Vec<_> = text.chars().collect();
        let source = Lrc::new(source);

-        let parser = language.create_parser();
+        let mut parser = language.create_parser();
+
+        if all_headings {
+            parser = Box::new(OopsAllHeadings::new(parser));
+        }

        let document = Document::new_from_vec(source.clone(), &parser, &self.dictionary);

@@ -641,7 +654,7 @@ mod tests {
        linter.import_words(vec![text.clone()]);
        dbg!(linter.dictionary.get_word_metadata_str(&text));

-        let lints = linter.lint(text, Language::Plain);
+        let lints = linter.lint(text, Language::Plain, false);
        assert!(lints.is_empty());
    }
 }
--- a/packages/chrome-plugin/src/ProtocolClient.ts
+++ b/packages/chrome-plugin/src/ProtocolClient.ts
@@ -1,4 +1,4 @@
-import type { Dialect, LintConfig } from 'harper.js';
+import type { Dialect, LintConfig, LintOptions } from 'harper.js';
 import type { UnpackedLintGroups } from 'lint-framework';
 import { LRUCache } from 'lru-cache';
 import type { ActivationKey } from './protocol';
@@ -9,16 +9,20 @@ export default class ProtocolClient {
 		ttl: 5_000,
 	});

-	private static cacheKey(text: string, domain: string): string {
-		return `${domain}:${text}`;
+	private static cacheKey(text: string, domain: string, options?: LintOptions): string {
+		return `${domain}:${text}:${options?.forceAllHeadings ?? ''}:${options?.language ?? ''}`;
 	}

-	public static async lint(text: string, domain: string): Promise<UnpackedLintGroups> {
-		const key = this.cacheKey(text, domain);
+	public static async lint(
+		text: string,
+		domain: string,
+		options?: LintOptions,
+	): Promise<UnpackedLintGroups> {
+		const key = this.cacheKey(text, domain, options);
 		let p = this.lintCache.get(key);
 		if (!p) {
 			p = chrome.runtime
-				.sendMessage({ kind: 'lint', text, domain })
+				.sendMessage({ kind: 'lint', text, domain, options })
 				.then((r) => r.lints as UnpackedLintGroups);
 			this.lintCache.set(key, p);
 		}
--- a/packages/chrome-plugin/src/background/index.ts
+++ b/packages/chrome-plugin/src/background/index.ts
@@ -162,7 +162,7 @@ async function handleLint(req: LintRequest): Promise<LintResponse> {
 		return { kind: 'lints', lints: {} };
 	}

-	const grouped = await linter.organizedLints(req.text);
+	const grouped = await linter.organizedLints(req.text, req.options);
 	const unpackedEntries = await Promise.all(
 		Object.entries(grouped).map(async ([source, lints]) => {
 			const unpacked = await Promise.all(lints.map((lint) => unpackLint(req.text, lint, linter)));
--- a/packages/chrome-plugin/src/contentScript/index.ts
+++ b/packages/chrome-plugin/src/contentScript/index.ts
@@ -13,22 +13,25 @@ if (isWordPress()) {
 	ProtocolClient.setDomainEnabled(window.location.hostname, true, false);
 }

-const fw = new LintFramework((text, domain) => ProtocolClient.lint(text, domain), {
-	ignoreLint: (hash) => ProtocolClient.ignoreHash(hash),
-	getActivationKey: () => ProtocolClient.getActivationKey(),
-	openOptions: () => ProtocolClient.openOptions(),
-	addToUserDictionary: (words) => ProtocolClient.addToUserDictionary(words),
-	reportError: (lint: UnpackedLint, ruleId: string) =>
-		ProtocolClient.openReportError(
-			padWithContext(lint.source, lint.span.start, lint.span.end, 15),
-			ruleId,
-			'',
-		),
-	setRuleEnabled: async (ruleId, enabled) => {
-		await ProtocolClient.setRuleEnabled(ruleId, enabled);
-		fw.update();
+const fw = new LintFramework(
+	(text, domain, options) => ProtocolClient.lint(text, domain, options),
+	{
+		ignoreLint: (hash) => ProtocolClient.ignoreHash(hash),
+		getActivationKey: () => ProtocolClient.getActivationKey(),
+		openOptions: () => ProtocolClient.openOptions(),
+		addToUserDictionary: (words) => ProtocolClient.addToUserDictionary(words),
+		reportError: (lint: UnpackedLint, ruleId: string) =>
+			ProtocolClient.openReportError(
+				padWithContext(lint.source, lint.span.start, lint.span.end, 15),
+				ruleId,
+				'',
+			),
+		setRuleEnabled: async (ruleId, enabled) => {
+			await ProtocolClient.setRuleEnabled(ruleId, enabled);
+			fw.update();
+		},
 	},
-});
+);

 function padWithContext(source: string, start: number, end: number, contextLength: number): string {
 	const normalizedStart = Math.max(0, Math.min(start, source.length));
@@ -40,7 +43,7 @@ function padWithContext(source: string, start: number, end: number, contextLengt
 }

 const keepAliveCallback = () => {
-	ProtocolClient.lint('', 'example.com');
+	ProtocolClient.lint('', 'example.com', {});

 	setTimeout(keepAliveCallback, 400);
 };
--- a/packages/chrome-plugin/src/protocol.ts
+++ b/packages/chrome-plugin/src/protocol.ts
@@ -1,4 +1,4 @@
-import type { Dialect, LintConfig } from 'harper.js';
+import type { Dialect, LintConfig, LintOptions } from 'harper.js';
 import type { UnpackedLintGroups } from 'lint-framework';

 export type Request =
@@ -40,6 +40,7 @@ export type LintRequest = {
 	kind: 'lint';
 	domain: string;
 	text: string;
+	options: LintOptions;
 };

 export type LintResponse = {
--- a/packages/harper.js/src/Linter.test.ts
+++ b/packages/harper.js/src/Linter.test.ts
@@ -347,6 +347,34 @@ for (const [linterName, Linter] of Object.entries(linters)) {

 		expect(text.slice(span.start, span.end)).toBe('sdssda');
 	});
+
+	test(`${linterName} lints headings when forced to mark them as such`, async () => {
+		const text = 'This sentences should be forced to title case.';
+
+		const linter = new LocalLinter({ binary });
+		const lints = await linter.lint(text, { forceAllHeadings: true });
+
+		expect(lints.length).toBe(1);
+
+		const lint = lints[0];
+		expect(lint.lint_kind()).toBe('Capitalization');
+		expect(lint.get_problem_text()).toBe(text);
+	});
+
+	test(`${linterName} lints headings when forced to mark them as such with organized mode`, async () => {
+		const text = 'This sentences should be forced to title case.';
+
+		const linter = new LocalLinter({ binary });
+		const lints = await linter.organizedLints(text, { forceAllHeadings: true });
+
+		const titleCaseLints = lints.UseTitleCase;
+		expect(titleCaseLints).not.toBeUndefined();
+		expect(titleCaseLints.length).toBe(1);
+
+		const lint = titleCaseLints[0];
+		expect(lint.lint_kind()).toBe('Capitalization');
+		expect(lint.get_problem_text()).toBe(text);
+	});
 }

 test('Linters have the same config format', async () => {
--- a/packages/harper.js/src/LocalLinter.ts
+++ b/packages/harper.js/src/LocalLinter.ts
@@ -35,7 +35,7 @@ export default class LocalLinter implements Linter {
 	async lint(text: string, options?: LintOptions): Promise<Lint[]> {
 		const inner = await this.inner;
 		const language = options?.language === 'plaintext' ? Language.Plain : Language.Markdown;
-		const lints = inner.lint(text, language);
+		const lints = inner.lint(text, language, options?.forceAllHeadings ?? false);

 		return lints;
 	}
@@ -43,7 +43,7 @@ export default class LocalLinter implements Linter {
 	async organizedLints(text: string, options?: LintOptions): Promise<Record<string, Lint[]>> {
 		const inner = await this.inner;
 		const language = options?.language === 'plaintext' ? Language.Plain : Language.Markdown;
-		const lintGroups = inner.organized_lints(text, language);
+		const lintGroups = inner.organized_lints(text, language, options?.forceAllHeadings ?? false);

 		const output: Record<string, Lint[]> = {};

--- a/packages/harper.js/src/main.ts
+++ b/packages/harper.js/src/main.ts
@@ -17,4 +17,7 @@ export type LintConfig = Record<string, boolean | null>;
 export interface LintOptions {
 	/** The markup language that is being passed. Defaults to `markdown`. */
 	language?: 'plaintext' | 'markdown';
+
+	/** Force the entirety of the document to be composed of headings. An undefined value is assumed to be false.*/
+	forceAllHeadings?: boolean;
 }
--- a/packages/lint-framework/src/lint/LintFramework.ts
+++ b/packages/lint-framework/src/lint/LintFramework.ts
@@ -1,6 +1,7 @@
+import type { LintOptions } from 'harper.js';
 import type { IgnorableLintBox } from './Box';
 import computeLintBoxes from './computeLintBoxes';
-import { isVisible } from './domUtils';
+import { isHeading, isVisible } from './domUtils';
 import Highlights from './Highlights';
 import PopupHandler from './PopupHandler';
 import type { UnpackedLint, UnpackedLintGroups } from './unpackLint';
@@ -27,7 +28,11 @@ export default class LintFramework {
 	private updateEventCallback: () => void;

 	/** Function used to fetch lints for a given text/domain. */
-	private lintProvider: (text: string, domain: string) => Promise<UnpackedLintGroups>;
+	private lintProvider: (
+		text: string,
+		domain: string,
+		options?: LintOptions,
+	) => Promise<UnpackedLintGroups>;
 	/** Actions wired by host environment (extension/app). */
 	private actions: {
 		ignoreLint?: (hash: string) => Promise<void>;
@@ -39,7 +44,11 @@ export default class LintFramework {
 	};

 	constructor(
-		lintProvider: (text: string, domain: string) => Promise<UnpackedLintGroups>,
+		lintProvider: (
+			text: string,
+			domain: string,
+			options?: LintOptions,
+		) => Promise<UnpackedLintGroups>,
 		actions: {
 			ignoreLint?: (hash: string) => Promise<void>;
 			getActivationKey?: () => Promise<ActivationKey>;
@@ -120,7 +129,9 @@ export default class LintFramework {
 					return { target: null as HTMLElement | null, lints: {} };
 				}

-				const lintsBySource = await this.lintProvider(text, window.location.hostname);
+				const lintsBySource = await this.lintProvider(text, window.location.hostname, {
+					forceAllHeadings: isHeading(target),
+				});
 				return { target: target as HTMLElement, lints: lintsBySource };
 			}),
 		);
--- a/packages/lint-framework/src/lint/domUtils.ts
+++ b/packages/lint-framework/src/lint/domUtils.ts
@@ -112,6 +112,17 @@ export function getRangeForTextSpan(target: Element, span: Span): Range | null {

 const sharedRange: Range | null = typeof document !== 'undefined' ? document.createRange() : null;

+/** Check if a node represents a heading (native heading tags or role="heading"). */
+export function isHeading(node: Node): boolean {
+	if (!(node instanceof Element)) return false;
+
+	const tag = node.tagName.toLowerCase();
+	if (/^h[1-6]$/.test(tag)) return true;
+
+	const role = node.getAttribute('role');
+	return role?.toLowerCase() === 'heading';
+}
+
 /** Check if an element is visible to the user.
 *
 * It is coarse and meant for performance improvements, not precision.*/