diff --git a/crates/proof/build.rs b/crates/proof/build.rs
index 0a9facda..b594efa0 100644
--- a/crates/proof/build.rs
+++ b/crates/proof/build.rs
@@ -102,7 +102,7 @@ fn main() {
         wanted_files += usize::from(wanted);
         let file = dir.as_ref().filter(|_| wanted).map(|d| d.join(rel)).filter(|f| f.is_file());
         if let (Some(d), None, true) = (&dir, &file, wanted) {
-            println!("cargo::{level}=CRAFT_I18N_DIR: {} is missing; craft-proof embeds none", d.join(rel).display());
+            println!("cargo::{level}=CRAFT_I18N_DIR: {} is missing; craft-proof embeds the rest without it", d.join(rel).display());
         }
         let (ty, empty, mac) = if bytes { ("&[u8]", "b\"\"", "include_bytes") } else { ("&str", "\"\"", "include_str") };
         // `language_data` only hands back a UTF-8 folder, so this is the path as it is.
diff --git a/crates/proof/src/cs/mod.rs b/crates/proof/src/cs/mod.rs
index 3f6e4a24..7cf8bbf4 100644
--- a/crates/proof/src/cs/mod.rs
+++ b/crates/proof/src/cs/mod.rs
@@ -163,6 +163,8 @@ mod tests {
 
     #[test]
     fn czech_dispatch_messages_options_and_mixed_spans() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         test_dict::install();
         assert!(crate::has_dictionary(Some("cs-CZ")));
         assert!(crate::is_correct_for("městě", Some("cze")));
diff --git a/crates/proof/src/es/mod.rs b/crates/proof/src/es/mod.rs
index 4d19462d..b9520794 100644
--- a/crates/proof/src/es/mod.rs
+++ b/crates/proof/src/es/mod.rs
@@ -245,6 +245,8 @@ mod tests {
     /// composed form (NFC) and keeps its own byte range, accents and all.
     #[test]
     fn decomposed_accents_are_checked_like_composed_ones() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         test_dict::install();
         for lang in VARIETIES {
             for text in ["esto también", "esto tambie\u{301}n", "una cancio\u{301}n y pingu\u{308}ino", "CANCIO\u{301}N", "nin\u{303}o"] {
@@ -289,6 +291,8 @@ mod tests {
 
     #[test]
     fn spanish_dispatch_messages_options_and_mixed_spans() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         test_dict::install();
         for tag in ["es-ES", "es-MX", "es-419", "es-AR", "es-UY", "spa"] {
             assert!(crate::has_dictionary(Some(tag)), "{tag}");
diff --git a/crates/proof/src/hunspell.rs b/crates/proof/src/hunspell.rs
index f1537edb..cc430374 100644
--- a/crates/proof/src/hunspell.rs
+++ b/crates/proof/src/hunspell.rs
@@ -150,27 +150,53 @@ fn xdg_data_home(xdg: Option<std::ffi::OsString>, home: Option<&Path>) -> Option
     xdg.map(PathBuf::from).filter(|p| p.is_absolute()).or_else(|| home.map(|h| h.join(".local/share")))
 }
 
-/// The first `<name>.aff`/`<name>.dic` pair found for any of `names` (`pl_PL`, `pl`), searching
-/// [`search_dirs`] (including LibreOffice's extension folder for the first name).
-///
-/// Lookup order: the dictionaries folders, then an installed Language pack for one of `names`
-/// (its `spelling.aff`/`spelling.dic`, [`crate::packs`]), then the system's folders.
+/// The first `<name>.aff`/`<name>.dic` pair found for any of `names` (`pl_PL`, `pl`), in the
+/// order of [`candidates`].
 pub fn find(names: &[&str]) -> Option<(PathBuf, PathBuf)> {
-    let lo = names.first().copied().map(lo_ext_dirs);
-    let (dirs, system) = search_tiers(lo.as_deref());
-    dirs.iter()
-        .find_map(|dir| find_in(dir, names))
-        .or_else(|| crate::packs::spelling_dirs(names).iter().find_map(|dir| find_in(dir, &[crate::packs::SPELLING])))
-        .or_else(|| system.iter().find_map(|dir| find_in(dir, names)))
+    candidates(names).into_iter().next()
 }
 
-/// Every `<name>.aff`/`<name>.dic` pair for `names`, in the order [`find`] prefers them: the
-/// dictionaries folders, then installed Language packs for `names` (their `spelling.aff`/
-/// `spelling.dic`), then the system's folders; folder by folder, each folder's in the order of
-/// `names`. A caller that can't read one tries the next.
+/// Every `<name>.aff`/`<name>.dic` pair for `names`, best first. A caller that can't read one
+/// tries the next. The order:
+///
+/// 1. the dictionaries folders ([`set_dictionary_dir`] and the others of [`search_dirs`]), any
+///    of `names`;
+/// 2. an installed Language pack of the first name's region or of the language alone
+///    ([`crate::packs`], `spelling.aff`/`spelling.dic`);
+/// 3. the system's folders, the first name's region (`pt_BR`, `pt-BR`);
+/// 4. any other installed pack of the language (another region: `pt-pt`);
+/// 5. the system's folders, the other names (`pt`).
 pub fn candidates(names: &[&str]) -> Vec<(PathBuf, PathBuf)> {
     let lo = names.first().copied().map(lo_ext_dirs);
-    candidates_in(&search_dirs(lo.as_deref()), names)
+    let (dirs, system) = search_tiers(lo.as_deref());
+    let (region_packs, other_packs) = crate::packs::spelling_dirs(names);
+    ordered(names, &dirs, &region_packs, &system, &other_packs)
+}
+
+/// [`candidates`] over the given folders.
+fn ordered(names: &[&str], dirs: &[PathBuf], region_packs: &[PathBuf], system: &[PathBuf], other_packs: &[PathBuf]) -> Vec<(PathBuf, PathBuf)> {
+    let norm = |n: &str| n.to_ascii_lowercase().replace('_', "-");
+    let first = names.first().map(|n| norm(n));
+    let (region, rest): (Vec<&str>, Vec<&str>) = names.iter().copied().partition(|n| Some(norm(n)) == first);
+    let pack: &[&str] = &[crate::packs::SPELLING];
+    let tiers = dirs
+        .iter()
+        .map(|d| (d, names))
+        .chain(region_packs.iter().map(|d| (d, pack)))
+        .chain(system.iter().map(|d| (d, &region[..])))
+        .chain(other_packs.iter().map(|d| (d, pack)))
+        .chain(system.iter().map(|d| (d, &rest[..])));
+    let mut out: Vec<(PathBuf, PathBuf)> = Vec::new();
+    for (dir, names) in tiers {
+        for n in names {
+            let aff = dir.join(format!("{n}.aff"));
+            let dic = dir.join(format!("{n}.dic"));
+            if aff.is_file() && dic.is_file() && !out.iter().any(|(_, d)| *d == dic) {
+                out.push((aff, dic));
+            }
+        }
+    }
+    out
 }
 
 /// [`candidates`] in the folders the user keeps dictionaries in for WordCraft ([`user_dirs`])
@@ -569,6 +595,56 @@ fn decode_utf8_dic(dic: &[u8]) -> Result<String, String> {
 mod tests {
     use super::*;
 
+    /// Another region's Language pack never beats the system's dictionary of the right region
+    /// (`pt-pt` pack vs system `pt_BR`; `de-ch` vs `de_DE`; `en-gb` vs `en_US`), but beats the
+    /// system's other names; the right region's pack beats the system; the dictionaries folder
+    /// beats everything.
+    #[test]
+    fn another_regions_pack_comes_after_the_systems_exact_region() {
+        let root = std::env::temp_dir().join(format!("wc-proof-order-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&root);
+        let pair = |dir: &Path, name: &str| {
+            std::fs::create_dir_all(dir).unwrap();
+            std::fs::write(dir.join(format!("{name}.aff")), "SET UTF-8\n").unwrap();
+            std::fs::write(dir.join(format!("{name}.dic")), "1\nx\n").unwrap();
+            dir.join(format!("{name}.dic"))
+        };
+        let (folder, system) = (root.join("folder"), root.join("system"));
+        let en: &[&str] = &["en_US", "en-US", "en", "en_CA", "en_GB", "en-GB", "en_AU"];
+        for (names, exact, other, cross) in [
+            (&["pt_BR", "pt-BR", "pt"][..], "pt_BR", "pt", "pt-pt"),
+            (&["de_DE", "de-DE", "de"][..], "de_DE", "de", "de-ch"),
+            (&["nl_NL", "nl-NL", "nl"][..], "nl_NL", "nl", "nl-be"),
+            (&["es_ES", "es-ES", "es_ANY", "es"][..], "es_ES", "es", "es-mx"),
+            (en, "en_US", "en_GB", "en-gb"),
+        ] {
+            let sys_exact = pair(&system, exact);
+            let sys_other = pair(&system, other);
+            let cross_pack = pair(&root.join("packs").join(cross), crate::packs::SPELLING);
+            let dics = |v: Vec<(PathBuf, PathBuf)>| v.into_iter().map(|(_, d)| d).collect::<Vec<_>>();
+            let got =
+                dics(ordered(names, &[], &[], std::slice::from_ref(&system), std::slice::from_ref(&cross_pack.parent().unwrap().to_path_buf())));
+            assert_eq!(got, [sys_exact.clone(), cross_pack.clone(), sys_other.clone()], "{names:?}");
+            // The region's own pack first, then the system's exact region.
+            let region_pack = pair(&root.join("packs").join(format!("{}-region", names[0])), crate::packs::SPELLING);
+            let got = dics(ordered(names, &[], &[region_pack.parent().unwrap().to_path_buf()], std::slice::from_ref(&system), &[]));
+            assert_eq!(got.first(), Some(&region_pack), "{names:?}");
+            assert_eq!(got.get(1), Some(&sys_exact), "{names:?}");
+            // The dictionaries folder before all of them, whatever name.
+            let mine = pair(&folder, other);
+            let got = dics(ordered(
+                names,
+                std::slice::from_ref(&folder),
+                &[region_pack.parent().unwrap().to_path_buf()],
+                std::slice::from_ref(&system),
+                &[],
+            ));
+            assert_eq!(got.first(), Some(&mine), "{names:?}");
+            assert_eq!(find_in(&folder, &[other]).map(|(_, d)| d), Some(mine));
+            let _ = std::fs::remove_dir_all(&root);
+        }
+    }
+
     /// WordCraft's own dictionaries folder under the user's application data is searched on every
     /// desktop system, after the setting and before the shared system locations (#1063).
     #[test]
diff --git a/crates/proof/src/hyphen.rs b/crates/proof/src/hyphen.rs
index 22271ca0..c1e1d56d 100644
--- a/crates/proof/src/hyphen.rs
+++ b/crates/proof/src/hyphen.rs
@@ -119,7 +119,8 @@ fn is_apostrophe(c: char) -> bool {
 }
 
 fn is_word_char(c: char) -> bool {
-    c.is_alphabetic() || is_apostrophe(c)
+    // A combining mark belongs to its letter (decomposed `a` + U+0301 is one letter, `á`).
+    c.is_alphabetic() || is_apostrophe(c) || unicode_normalization::char::is_combining_mark(c)
 }
 
 /// Unrestricted break points of one lowercase core (letters and `'` only, no leading/trailing `'`).
@@ -184,6 +185,26 @@ fn core_breaks(core: &[char], lang: ProofLang) -> (Vec<usize>, Source) {
     (heuristic_points(core), Source::Heuristic)
 }
 
+/// `core` composed (NFC), with the index in `core` where each composed character's base starts
+/// (`None` for a character that isn't the first of its base's group). Never longer than `core`.
+fn composed_chars(core: &[char]) -> (Vec<char>, Vec<Option<usize>>) {
+    use unicode_normalization::UnicodeNormalization;
+    use unicode_normalization::char::is_combining_mark;
+    let mut nfc: Vec<char> = Vec::with_capacity(core.len());
+    let mut starts: Vec<Option<usize>> = Vec::with_capacity(core.len());
+    let mut i = 0;
+    while i < core.len() {
+        let end = core.get(i + 1..).and_then(|rest| rest.iter().position(|&c| !is_combining_mark(c))).map_or(core.len(), |n| i + 1 + n);
+        let group: String = core.get(i..end).unwrap_or_default().iter().collect();
+        for (k, c) in group.nfc().enumerate() {
+            nfc.push(c);
+            starts.push((k == 0).then_some(i));
+        }
+        i = end;
+    }
+    (nfc, starts)
+}
+
 /// Does a pack's `pats` hyphenate `core` in `lang`? Russian, Bulgarian and Turkish: a word in
 /// their script (the guard their rules use). Polish, Portuguese, Italian and German: every word,
 /// as their embedded patterns do. Any other language: a word whose letters the patterns know.
@@ -249,6 +270,16 @@ pub fn word_breaks(word: &str) -> (Vec<usize>, Source) {
 /// run is hyphenated separately). No break is ever placed next to an apostrophe or non-letter.
 pub fn word_breaks_in(word: &str, lang: ProofLang) -> (Vec<usize>, Source) {
     let chars: Vec<char> = word.chars().collect();
+    // Patterns are composed text (NFC), as spelling reads words: a decomposed word (`a` + U+0301)
+    // is hyphenated composed, and the breaks mapped back to its own chars.
+    if unicode_normalization::is_nfc_quick(word.chars()) != unicode_normalization::IsNormalized::Yes {
+        let (nfc, starts) = composed_chars(&chars);
+        if nfc.len() < chars.len() {
+            let composed: String = nfc.iter().collect();
+            let (pts, src) = word_breaks_in(&composed, lang);
+            return (pts.into_iter().filter_map(|i| starts.get(i).copied().flatten()).collect(), src);
+        }
+    }
     let mut out = Vec::new();
     let mut src = Source::None;
     let mut i = 0;
diff --git a/crates/proof/src/id/mod.rs b/crates/proof/src/id/mod.rs
index 53ba16ec..10306a75 100644
--- a/crates/proof/src/id/mod.rs
+++ b/crates/proof/src/id/mod.rs
@@ -170,6 +170,8 @@ mod tests {
 
     #[test]
     fn indonesian_dispatch_messages_options_and_mixed_spans() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         test_dict::install();
         assert!(crate::has_dictionary(Some("id-ID")));
         assert!(crate::is_correct_for("rumah", Some("ind")));
diff --git a/crates/proof/src/lib.rs b/crates/proof/src/lib.rs
index 6da047c9..68043b6d 100644
--- a/crates/proof/src/lib.rs
+++ b/crates/proof/src/lib.rs
@@ -601,15 +601,44 @@ pub fn unreadable_dictionary(lang: Option<&str>) -> Option<(&'static str, std::p
 
 /// Did the Hunspell dictionary of `lang` load? `None` for languages that use none (English).
 fn dictionary_loaded(lang: ProofLang) -> Option<bool> {
+    if let Some(l) = lang.spelling_locale() {
+        return Some(pack_lang::has_dictionary(l));
+    }
     language(lang).map(|l| l.slot.has_dictionary())
 }
 
 /// The Hunspell name `lang` needs when `installed` is false (the first name its module looks for;
 /// a Spanish variety's is its own: `es_ES`, `es_MX`, `es_419`, `es_UY`).
 fn dictionary_needed(lang: ProofLang, installed: bool) -> Option<&'static str> {
-    language(lang).filter(|_| !installed).map(|l| l.slot.name())
+    if installed {
+        return None;
+    }
+    if let Some(l) = lang.spelling_locale() {
+        return pack_lang::names(l).first().and_then(|n| interned(n));
+    }
+    language(lang).map(|l| l.slot.name())
 }
 
+/// `name` as a `&'static str` (the API hands out Hunspell names that way), for at most
+/// [`MAX_INTERNED`] names; `None` after that.
+fn interned(name: &str) -> Option<&'static str> {
+    // ponytail: leaks each distinct pack dictionary name once, capped; a `Cow` API if more matter.
+    static NAMES: std::sync::Mutex<Vec<&'static str>> = std::sync::Mutex::new(Vec::new());
+    let mut names = NAMES.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
+    if let Some(n) = names.iter().find(|n| **n == name) {
+        return Some(n);
+    }
+    if names.len() >= MAX_INTERNED {
+        return None;
+    }
+    let n: &'static str = Box::leak(name.to_string().into_boxed_str());
+    names.push(n);
+    Some(n)
+}
+
+/// Most pack dictionary names [`interned`] keeps.
+const MAX_INTERNED: usize = 256;
+
 /// Is `word` spelled correctly in the run's proofing language? A language without a dictionary
 /// can't be checked, so every word counts as correct (no red underlines for it).
 pub fn is_correct_for(word: &str, lang: Option<&str>) -> bool {
@@ -806,6 +835,38 @@ pub(crate) fn is_address(token: &str) -> bool {
     token.contains("://") || token.contains('@') || token.starts_with("www.")
 }
 
+/// The spelling mark's message in `lang`: a built-in language's own, a pack language's when we
+/// have it (German, Bulgarian and other common ones), else English.
+fn spelling_message(lang: ProofLang) -> &'static str {
+    if let Some(l) = language(lang) {
+        return l.message;
+    }
+    let pack = lang.pack_locale();
+    let primary = match lang {
+        ProofLang::De => "de",
+        ProofLang::Bg => "bg",
+        _ => pack.as_ref().map_or("", PackLocale::primary),
+    };
+    match primary {
+        "de" => "Möglicher Rechtschreibfehler",
+        "bg" => "Възможна правописна грешка",
+        "nl" => "Mogelijke spelfout",
+        "fr" => "Faute d’orthographe possible",
+        "sv" => "Möjligt stavfel",
+        "da" => "Mulig stavefejl",
+        "nb" | "nn" | "no" => "Mulig stavefeil",
+        "fi" => "Mahdollinen kirjoitusvirhe",
+        "uk" => "Можлива орфографічна помилка",
+        "el" => "Πιθανό ορθογραφικό λάθος",
+        "ca" => "Possible error ortogràfic",
+        "ro" => "Posibilă greșeală de ortografie",
+        "hu" => "Lehetséges helyesírási hiba",
+        "sk" => "Možná pravopisná chyba",
+        "sl" => "Možna pravopisna napaka",
+        _ => "Possible spelling mistake",
+    }
+}
+
 /// The spelling issue of the word at `a..b` of `text`, if it is misspelled in `lang`. Words in
 /// web and e-mail addresses are skipped (unless `opts` says otherwise); `internet` is the
 /// classification of the word's enclosing token, from [`enclosing_token`].
@@ -815,7 +876,7 @@ fn spelling_issue(text: &str, a: usize, b: usize, lang: ProofLang, opts: &Option
     if (opts.ignore_internet && internet) || (lang.is_english() && vi::is_vietnamese_word(w)) || is_correct_in_with(w, lang, opts) {
         return None;
     }
-    let message = language(lang).map_or("Possible spelling mistake", |l| l.message);
+    let message = spelling_message(lang);
     Some(Issue { start: a, end: b, kind: IssueKind::Spelling, message: message.into(), suggestions: Vec::new(), lang })
 }
 
@@ -1226,6 +1287,32 @@ mod tests {
         assert_ne!(english_source(ProofLang::En), Some(EnglishSource::Hunspell(dir.join("en_US.dic"))));
     }
 
+    /// A document tagging thousands of languages keeps the remembered pack hyphenation lookups
+    /// bounded, and stays quick.
+    #[test]
+    fn many_pack_languages_keep_the_hyphenation_cache_bounded() {
+        let _guard = DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
+        set_dictionaries_folder(Some(shared_test_folder()));
+        let root = std::env::temp_dir().join(format!("wc-proof-many-tags-{}", std::process::id()));
+        std::fs::create_dir_all(&root).unwrap();
+        packs::set_packs_dir(Some(root.clone()));
+        let start = std::time::Instant::now();
+        for i in 0..3000 {
+            let lang = ProofLang::from_tag(Some(&format!(
+                "q{}{}-{}",
+                (b'a' + (i / 1000) as u8) as char,
+                (b'a' + (i / 100 % 10) as u8) as char,
+                100 + i % 100
+            )));
+            assert!(lang.pack_locale().is_some(), "{lang:?}");
+            let _ = hyphen::hyphenate_word_in("hyphenation", &hyphen::Limits::default(), lang);
+            assert!(packs::hyphenation_lookups() <= 256);
+        }
+        assert!(start.elapsed() < std::time::Duration::from_secs(5), "{:?}", start.elapsed());
+        packs::set_packs_dir(None);
+        let _ = std::fs::remove_dir_all(&root);
+    }
+
     /// CP4.2: with no embedded word list, English looks in the dictionaries folder, then an
     /// installed English Language pack, then the system's Hunspell, then the built-in list.
     #[test]
@@ -1476,6 +1563,18 @@ mod tests {
         let _ = std::fs::remove_dir_all(&root);
     }
 
+    /// German, Bulgarian and pack languages mark spelling in their own language where we have
+    /// the words for it, like the built-in ones; English otherwise.
+    #[test]
+    fn spelling_messages_are_in_the_language() {
+        assert_eq!(spelling_message(ProofLang::De), "Möglicher Rechtschreibfehler");
+        assert_eq!(spelling_message(ProofLang::Bg), "Възможна правописна грешка");
+        assert_eq!(spelling_message(ProofLang::from_tag(Some("fr-CA"))), "Faute d’orthographe possible");
+        assert_eq!(spelling_message(ProofLang::Pl), "Możliwy błąd pisowni");
+        assert_eq!(spelling_message(ProofLang::from_tag(Some("xh"))), "Possible spelling mistake");
+        assert_eq!(spelling_message(ProofLang::En), "Possible spelling mistake");
+    }
+
     /// CP4.2: a language with no tools of its own (Dutch) is spell-checked, given suggestions and
     /// hyphenated from its installed Language pack; removed, it is unchecked again; English is
     /// unaffected. No grammar rules for it.
@@ -1511,6 +1610,10 @@ mod tests {
         let issues = check_text(text, &[(0..text.len(), nl)]);
         assert_eq!(issues.len(), 1, "{issues:?}");
         assert_eq!((issues[0].kind, &text[issues[0].start..issues[0].end], issues[0].lang), (IssueKind::Spelling, "fietz", nl));
+        assert_eq!(issues[0].message, "Mogelijke spelfout", "the language's own message");
+        assert_eq!((missing_dictionary(Some("nl-NL")), unreadable_dictionary(Some("nl-NL"))), (None, None));
+        let missing_fr = missing_dictionary(Some("fr-FR"));
+        assert!(missing_fr.is_none_or(|n| n == "fr_FR"), "{missing_fr:?}");
         assert!(suggest_in("fietz", 5, nl).contains(&"fiets".to_string()), "{:?}", suggest_in("fietz", 5, nl));
         assert!(check_grammar_in("de de huis", nl).is_empty(), "no grammar rules");
         assert_eq!(hyphen::hyphenate_word_in("xxnaxx", &hyphen::Limits::default(), nl), "xx-naxx");
@@ -1521,6 +1624,10 @@ mod tests {
         packs::reload();
         assert!(is_correct_in("fietz", nl) && !nl.is_proofed());
         assert!(dictionary_load_error(nl).unwrap_or_default().contains("unsupported encoding"));
+        let (name, file, reason) = unreadable_dictionary(Some("nl-NL")).unwrap();
+        assert_eq!((name, file), ("nl_NL", pack.join("spelling.dic")));
+        assert!(reason.contains("unsupported encoding"), "{reason}");
+        assert_eq!(missing_dictionary(Some("nl-NL")), Some("nl_NL"), "as for the other languages");
         // Removed: unchecked again.
         std::fs::remove_dir_all(&pack).unwrap();
         packs::reload();
@@ -1608,11 +1715,23 @@ mod tests {
         let (ru, el) = (ProofLang::Ru, ProofLang::from_tag(Some("el")));
         let before = [hyphen::hyphenate_word_in("hyphenation", &lim, ru), hyphen::hyphenate_word_in("hyphenation", &lim, el)];
         write_pack(&root, "ru", &[("hyphenation.pat", "1на 1ка\n".as_bytes())]);
-        write_pack(&root, "el", &[("hyphenation.pat", "1να 1κα\n".as_bytes())]);
+        write_pack(&root, "el", &[("hyphenation.pat", "1να 1κα 1κά\n".as_bytes())]);
         packs::set_packs_dir(Some(root.clone()));
         assert_eq!([hyphen::hyphenate_word_in("hyphenation", &lim, ru), hyphen::hyphenate_word_in("hyphenation", &lim, el)], before);
         assert_eq!(hyphen::hyphenate_word_in("канака", &lim, ru), "ка-на-ка", "a Russian word uses the pack");
         assert_eq!(hyphen::hyphenate_word_in("κανακα", &lim, el), "κα-να-κα");
+        // Decomposed text is composed for the patterns, as spelling does, and stays as it was
+        // (patterns no fallback would give: `καν-ακά`).
+        write_pack(&root, "grc", &[("hyphenation.pat", "ν1α ν1ά 2κ ά2\n".as_bytes())]);
+        packs::reload();
+        let grc = ProofLang::from_tag(Some("grc"));
+        assert_eq!(hyphen::hyphenate_word_in("κανακά", &lim, grc), "καν-ακά");
+        assert_eq!(hyphen::hyphenate_word_in("κανακα\u{301}", &lim, grc), "καν-ακα\u{301}");
+        assert!(hyphen::hyphenate_word_in("κανάκανα", &lim, grc).starts_with("καν-ά"), "{}", hyphen::hyphenate_word_in("κανάκανα", &lim, grc));
+        assert_eq!(
+            hyphen::hyphenate_word_in("κανα\u{301}κανα", &lim, grc),
+            hyphen::hyphenate_word_in("κανάκανα", &lim, grc).replace('ά', "α\u{301}")
+        );
         packs::set_packs_dir(None);
         set_dictionaries_folder(Some(shared_test_folder()));
         let _ = std::fs::remove_dir_all(&root);
@@ -1631,8 +1750,11 @@ mod tests {
             std::fs::write(dir.join("LICENCES").join("BIG"), &big).unwrap();
         }
         packs::set_packs_dir(Some(root.clone()));
+        let before = packs::LICENCE_BYTES_READ.load(std::sync::atomic::Ordering::Relaxed);
         let from_packs: usize = packs::licence_texts().iter().filter(|(t, _)| t.contains(": BIG")).map(|(_, x)| x.len()).sum();
         assert!(from_packs > 0 && from_packs <= 16 << 20, "{from_packs}");
+        let read = packs::LICENCE_BYTES_READ.load(std::sync::atomic::Ordering::Relaxed) - before;
+        assert!(read <= 16 << 20, "{read} bytes read: a file over what is left is never read");
         packs::set_packs_dir(None);
         set_dictionaries_folder(Some(shared_test_folder()));
         let _ = std::fs::remove_dir_all(&root);
@@ -1803,6 +1925,8 @@ mod tests {
     /// with the rule; a plain paragraph's does, and later sentences in the item are still checked.
     #[test]
     fn list_item_first_word_needs_no_capital() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let grammar = |t: &str, lang: ProofLang, list: bool| -> Vec<String> {
             check_text_with(t, &[(0..t.len(), lang)], &Options::default(), true, list)
                 .into_iter()
@@ -1838,6 +1962,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn spelling() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         for w in [
             "if",
             "we",
@@ -1869,6 +1995,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn ically_adverbs_are_known() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         for w in ["specifically", "scientifically", "automatically", "dramatically", "Specifically"] {
             assert!(is_correct(w), "{w}");
         }
@@ -1882,6 +2010,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn non_ic_words_do_not_take_ally() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         for (base, wrong) in [("desktop", "desktopally"), ("house", "houseally"), ("final", "finalally"), ("green", "greenally")] {
             assert!(is_correct(base), "{base}");
             assert!(!is_correct(wrong), "{wrong}");
@@ -1892,6 +2022,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn common_modern_words() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         for w in [
             "desktop",
             "Desktops",
@@ -1929,6 +2061,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn british_spellings_are_known() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         for w in [
             "judgement",
             "defence",
@@ -1976,6 +2110,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn english_dialects_flag_each_others_spellings() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let (us, gb, ca) = (ProofLang::En, ProofLang::EnGb, ProofLang::EnCa);
         // (word, right in en-US, right in en-CA, right in en-GB)
         let cases = [
@@ -2069,6 +2205,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn british_words_reported_in_issue_40_are_right_in_en_gb() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let (us, gb, ca) = (ProofLang::En, ProofLang::EnGb, ProofLang::EnCa);
         // (word, right in en-US, right in en-CA, right in en-GB)
         let cases = [
@@ -2115,6 +2253,8 @@ mod tests {
     /// with their inflections.
     #[test]
     fn more_british_spellings_are_right_in_en_gb() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let gb = ProofLang::EnGb;
         assert_eq!(ProofLang::from_tag(Some("en-AU")), gb);
         for w in [
@@ -2292,6 +2432,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn user_dictionary_accepts_the_other_dialects_spelling() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         add_word("savour");
         assert!(is_correct_in("savour", ProofLang::En), "a word the user added is never flagged");
         assert!(!is_correct_in("savor", ProofLang::EnGb));
@@ -2322,6 +2464,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn address_token_covers_every_word_split_out_of_it() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         // #1335: one whitespace-delimited token, however punctuation splits it, has one
         // web/e-mail classification, shared by all its words.
         let t = "zxq@mail.example.com,blorp;qwirpy wugwug";
@@ -2337,6 +2481,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn address_after_a_wide_space_is_an_internet_token() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         // A web or e-mail address after a no-break space, a narrow no-break space, a figure space
         // or an ideographic space is skipped, as it is after a plain space.
         let t = "see\u{a0}https://xyzq.example/blorp and\u{3000}www.qwirpy.example or\u{a0}zxq@mail.example \
@@ -2350,6 +2496,8 @@ mod tests {
 
     #[test]
     fn spelling_scales_over_one_long_token() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         // #1335: thousands of punctuation-separated words inside a single
         // whitespace-free token: one classification for the token, one issue per
         // misspelled word, through every public spelling entry point. Without the Language data
@@ -2416,6 +2564,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn user_dictionary_works() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         assert!(!is_correct("zxqwordcrafty"));
         add_word("zxqwordcrafty");
         assert!(is_correct("zxqwordcrafty"));
@@ -2449,6 +2599,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn hostile_dictionary_files_are_capped() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let dir = std::env::temp_dir().join(format!("wc-dict-{}-{}", std::process::id(), "hostile"));
         let _ = std::fs::create_dir_all(&dir);
         let path = dir.join("custom-dictionary.txt");
@@ -2472,6 +2624,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn saving_merges_with_the_file() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let dir = std::env::temp_dir().join(format!("wc-dict-{}-{}", std::process::id(), "merge"));
         let _ = std::fs::create_dir_all(&dir);
         let path = dir.join("custom-dictionary.txt");
@@ -2490,6 +2644,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn ignored_words_are_not_dictionary_words() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         assert!(!is_correct("zxqignoredword"));
         ignore_word("ZxqIgnoredWord");
         assert!(is_correct("zxqignoredword"));
@@ -2534,6 +2690,8 @@ mod tests {
     /// byte range of what was typed, and it is checked as its composed form in every language.
     #[test]
     fn decomposed_words_stay_whole() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let text = "tambie\u{301}n, cafe\u{301}  \u{301}x";
         let ws: Vec<&str> = words(text).into_iter().map(|(a, b)| &text[a..b]).collect();
         assert_eq!(ws, ["tambie\u{301}n", "cafe\u{301}", "\u{301}x"]);
@@ -2625,6 +2783,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn each_language_uses_its_own_tools() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         pl::test_dict::install();
         let pl = "Zażółć gęślą jaźń, chrząszcz brzmi w trzcinie.";
         assert!(check_spelling_in(pl, ProofLang::Pl).is_empty(), "{:?}", check_spelling_in(pl, ProofLang::Pl));
@@ -2646,6 +2806,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn italian_uses_its_own_tools() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         it::test_dict::install();
         let it = "La città vecchia ha un bel caffè in piazza.";
         assert!(check_spelling_in(it, ProofLang::It).is_empty(), "{:?}", check_spelling_in(it, ProofLang::It));
@@ -2662,6 +2824,8 @@ mod tests {
     #[cfg_attr(not(craft_proof_data), ignore = "needs the Language data (CRAFT_I18N_DIR)")]
     #[test]
     fn mixed_language_paragraphs_check_each_run_in_its_language() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         pl::test_dict::install();
         // A Polish paragraph quoting English: English spelling and rules inside the quote only.
         let t = "Napisał „the quick brown fox is is here” i poszedł spać, bo żeka wylała.";
diff --git a/crates/proof/src/no_data.rs b/crates/proof/src/no_data.rs
index e050bb60..3f68b718 100644
--- a/crates/proof/src/no_data.rs
+++ b/crates/proof/src/no_data.rs
@@ -118,6 +118,8 @@ fn hyphenation_is_off_where_it_needs_data() {
 /// Every public entry point, in every language, on every sample: no panic.
 #[test]
 fn every_public_function_runs_without_data() {
+    // English results depend on the dictionaries other tests install.
+    let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
     let lim = Limits { min_word: 0, after_first: 0, before_last: 0, capitalized: true };
     let opts = Options { ignore_uppercase: false, ignore_numbers: false, ignore_internet: false };
     for text in SAMPLES {
diff --git a/crates/proof/src/packs.rs b/crates/proof/src/packs.rs
index 66368d95..da1384da 100644
--- a/crates/proof/src/packs.rs
+++ b/crates/proof/src/packs.rs
@@ -21,6 +21,7 @@
 //! link); a pack whose `pack.toml` is missing, unreadable or names a path outside the pack is
 //! skipped and reported by [`load_errors`]. Nothing here panics on a hostile pack.
 
+use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, PoisonError, RwLock, RwLockReadGuard, RwLockWriteGuard};
 
@@ -31,6 +32,8 @@ use crate::patterns::Patterns;
 pub(crate) const SPELLING: &str = "spelling";
 /// A pack's hyphenation patterns.
 const HYPHENATION: &str = "hyphenation.pat";
+/// Most languages whose pack patterns are remembered (a document may tag thousands).
+const MAX_HYPHENATION_LOOKUPS: usize = 256;
 /// A pack's description.
 const PACK_TOML: &str = "pack.toml";
 /// A pack's licence texts.
@@ -76,15 +79,16 @@ struct Holds {
 struct State {
     dir: Option<PathBuf>,
     scan: Option<Arc<Scan>>,
-    /// Each language's pack patterns once looked up (`None`: no pack has them).
-    hyphenation: Vec<(ProofLang, Option<Arc<Patterns>>)>,
+    /// Each language's pack patterns once looked up (`None`: no pack has them), at most
+    /// [`MAX_HYPHENATION_LOOKUPS`] languages (cleared when full).
+    hyphenation: BTreeMap<ProofLang, Option<Arc<Patterns>>>,
     /// (locale, reason) of pack hyphenation files that failed to load.
     hyphenation_errors: Vec<(String, String)>,
     /// Counts changes, so a scan or load that started before one is not kept.
     changes: u64,
 }
 
-static STATE: RwLock<State> = RwLock::new(State { dir: None, scan: None, hyphenation: Vec::new(), hyphenation_errors: Vec::new(), changes: 0 });
+static STATE: RwLock<State> = RwLock::new(State { dir: None, scan: None, hyphenation: BTreeMap::new(), hyphenation_errors: Vec::new(), changes: 0 });
 
 fn read() -> RwLockReadGuard<'static, State> {
     STATE.read().unwrap_or_else(PoisonError::into_inner)
@@ -148,22 +152,26 @@ pub fn licence_texts() -> Vec<(String, String)> {
     if !crate::data::EN_US_DIC.is_empty() {
         out.push(("English word list and hyphenation (Moby Hyphenator II)".into(), MOBY_NOTICE.into()));
     }
-    out.push(("English core word list".into(), CORE_LIST_NOTICE.into()));
+    out.push(("English word list built into craft-proof".into(), CORE_LIST_NOTICE.into()));
     out.extend(crate::data::EMBEDDED_LICENCES.iter().map(|(t, x)| ((*t).to_string(), (*x).to_string())));
-    let mut total: u64 = 0;
-    'packs: for (p, _) in &scan().packs {
-        for (file, text) in licence_files(&p.path) {
-            total = total.saturating_add(text.len() as u64);
-            if total > MAX_LICENCE_TOTAL {
-                log::warn!("Language pack licences: over {MAX_LICENCE_TOTAL} bytes in all; the rest aren't shown");
-                break 'packs;
-            }
+    // Each file is checked against what is left before it is read, so no more is ever read.
+    let mut left: u64 = MAX_LICENCE_TOTAL;
+    for (p, _) in &scan().packs {
+        for (file, text) in licence_files(&p.path, &mut left) {
             out.push((format!("{} ({}): {file}", p.name, p.locale), text));
         }
+        if left == 0 {
+            log::warn!("Language pack licences: {MAX_LICENCE_TOTAL} bytes in all; the rest aren't shown");
+            break;
+        }
     }
     out
 }
 
+/// Licence bytes read so far (tests check the cap holds while reading, not only after).
+#[cfg(test)]
+pub(crate) static LICENCE_BYTES_READ: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
+
 /// Most bytes of pack licence text [`licence_texts`] reads in all.
 const MAX_LICENCE_TOTAL: u64 = 16 << 20;
 
@@ -171,9 +179,9 @@ const MAX_LICENCE_TOTAL: u64 = 16 << 20;
 const MOBY_NOTICE: &str = "The Moby Hyphenator II word list by Grady Ward (Project Gutenberg eBook #3204) is in the public domain. \
 The English hyphenation patterns were trained from it for the Craft apps and are distributed with them under MIT OR Apache-2.0.";
 
-/// The notice of the core word list built into the crate (`data/en-core.txt`).
-const CORE_LIST_NOTICE: &str = "The core English word list built into craft-proof is taken from the Moby Hyphenator II word list by Grady Ward \
-(public domain), ranked by public-domain Project Gutenberg books. It is in the public domain.";
+/// The notice of the word list built into the crate (`data/en-words.dic`).
+const CORE_LIST_NOTICE: &str = "The English word list built into craft-proof is the Moby Hyphenator II word list by Grady Ward \
+(Project Gutenberg eBook #3204), which is in the public domain.";
 
 /// The locales whose Language data is embedded in this build (`en-us`…, and in a Language build
 /// the ones it names; `CRAFT_PROOF_EMBED`).
@@ -354,7 +362,7 @@ fn read_capped(p: &Path, cap: u64) -> Result<Vec<u8>, String> {
 }
 
 /// The licence texts in a pack's `LICENCES/` folder, by file name.
-fn licence_files(pack: &Path) -> Vec<(String, String)> {
+fn licence_files(pack: &Path, left: &mut u64) -> Vec<(String, String)> {
     let dir = pack.join(LICENCES);
     if !std::fs::symlink_metadata(&dir).is_ok_and(|m| m.is_dir()) {
         return Vec::new();
@@ -370,7 +378,17 @@ fn licence_files(pack: &Path) -> Vec<(String, String)> {
     names
         .into_iter()
         .filter_map(|n| {
-            let bytes = read_capped(&dir.join(&n), MAX_LICENCE).ok()?;
+            let path = dir.join(&n);
+            let size = std::fs::symlink_metadata(&path).ok().filter(std::fs::Metadata::is_file)?.len();
+            if size > (*left).min(MAX_LICENCE) {
+                // Over what is left: none of the rest is read either.
+                *left = 0;
+                return None;
+            }
+            let bytes = read_capped(&path, size.min(MAX_LICENCE)).ok()?;
+            *left = left.saturating_sub(bytes.len() as u64);
+            #[cfg(test)]
+            LICENCE_BYTES_READ.fetch_add(bytes.len() as u64, std::sync::atomic::Ordering::Relaxed);
             Some((n, String::from_utf8_lossy(&bytes).into_owned()))
         })
         .collect()
@@ -426,12 +444,33 @@ fn packs_for(locales: &[String], has: impl Fn(&Holds) -> bool) -> Vec<PathBuf> {
 }
 
 /// The folders of the installed packs with a spelling dictionary for the Hunspell dictionary
-/// `names` (`pl_PL`, `pl`), best first ([`crate::hunspell::find`] reads them).
-pub(crate) fn spelling_dirs(names: &[&str]) -> Vec<PathBuf> {
+/// `names` (`pt_BR`, `pt-BR`, `pt`), best first ([`crate::hunspell::find`] reads them), in two
+/// tiers: the packs of the first name's own region (`pt-br`) or of the language alone (`pt`), then
+/// every other one (the other names' regions, then any other region of the language: `pt-pt`).
+/// The system's exact-region dictionaries are searched between the two, so another region's pack
+/// never beats them.
+pub(crate) fn spelling_dirs(names: &[&str]) -> (Vec<PathBuf>, Vec<PathBuf>) {
     if read().dir.is_none() {
-        return Vec::new();
+        return (Vec::new(), Vec::new());
     }
-    packs_for(&locales_for(names), |h| h.spelling)
+    let all = packs_for(&locales_for(names), |h| h.spelling);
+    let region = region_locales(names);
+    let scan = scan();
+    let in_region = |path: &PathBuf| scan.packs.iter().any(|(p, _)| &p.path == path && region.contains(&p.locale));
+    all.into_iter().partition(in_region)
+}
+
+/// The pack locales of `names`' own region: the first name's (`pt_BR` → `pt-br`) and the language
+/// alone (`pt`) when it is written in the same script.
+pub(crate) fn region_locales(names: &[&str]) -> Vec<String> {
+    let Some(first) = names.first() else { return Vec::new() };
+    let mut out = vec![first.to_ascii_lowercase().replace('_', "-")];
+    let primary = first.split(['_', '-']).next().unwrap_or_default().to_ascii_lowercase();
+    if same_script(first, &primary) && !out.contains(&primary) {
+        out.push(primary);
+    }
+    out.retain(|l| is_locale(l));
+    out
 }
 
 /// The pack locales whose patterns hyphenate `lang`, best first; none for English (embedded)
@@ -465,7 +504,7 @@ pub(crate) fn hyphenation(lang: ProofLang) -> Option<Arc<Patterns>> {
     let changes = {
         let s = read();
         s.dir.as_ref()?;
-        if let Some((_, p)) = s.hyphenation.iter().find(|(l, _)| *l == lang) {
+        if let Some(p) = s.hyphenation.get(&lang) {
             return p.clone();
         }
         s.changes
@@ -486,8 +525,12 @@ pub(crate) fn hyphenation(lang: ProofLang) -> Option<Arc<Patterns>> {
         }
     }
     let mut s = write();
-    if s.changes == changes && !s.hyphenation.iter().any(|(l, _)| *l == lang) {
-        s.hyphenation.push((lang, found.clone()));
+    if s.changes == changes && !s.hyphenation.contains_key(&lang) {
+        // ponytail: cleared when full, an LRU if many languages each need their patterns.
+        if s.hyphenation.len() >= MAX_HYPHENATION_LOOKUPS {
+            s.hyphenation.clear();
+        }
+        s.hyphenation.insert(lang, found.clone());
         for e in errors {
             if !s.hyphenation_errors.contains(&e) {
                 s.hyphenation_errors.push(e);
@@ -497,6 +540,12 @@ pub(crate) fn hyphenation(lang: ProofLang) -> Option<Arc<Patterns>> {
     found
 }
 
+/// How many languages' pack patterns are remembered now.
+#[cfg(test)]
+pub(crate) fn hyphenation_lookups() -> usize {
+    read().hyphenation.len()
+}
+
 /// A pack's `hyphenation.pat` (UTF-8 TeX or plain Liang patterns, at most the dictionary cap).
 fn load_patterns(path: &Path) -> Result<Patterns, String> {
     let bytes = read_capped(path, crate::hunspell::MAX_FILE)?;
@@ -534,6 +583,10 @@ mod tests {
     #[test]
     fn dictionary_names_map_to_pack_locales() {
         assert_eq!(locales_for(&["pt_BR", "pt-BR", "pt"]), ["pt-br", "pt"]);
+        assert_eq!(region_locales(&["pt_BR", "pt-BR", "pt"]), ["pt-br", "pt"]);
+        assert_eq!(region_locales(&["en_US", "en-US", "en", "en_GB"]), ["en-us", "en"]);
+        assert_eq!(region_locales(&["sr_Latn", "sr-Latn"]), ["sr-latn"]);
+        assert!(region_locales(&[]).is_empty());
         assert_eq!(locales_for(&["es_419", "es"]), ["es-419", "es"]);
         assert_eq!(locales_for(&["../x", "a b"]), Vec::<String>::new());
     }
diff --git a/crates/proof/src/ru/extra.rs b/crates/proof/src/ru/extra.rs
index 988a24ac..26551e0d 100644
--- a/crates/proof/src/ru/extra.rs
+++ b/crates/proof/src/ru/extra.rs
@@ -156,7 +156,10 @@ fn forms(base: &str, class: &str) -> Vec<String> {
 mod tests {
     use super::*;
 
-    #[cfg_attr(not(craft_proof_embed = "ru"), ignore = "needs the ru Language data (CRAFT_I18N_DIR, CRAFT_PROOF_EMBED=ru)")]
+    #[cfg_attr(
+        not(craft_proof_embed = "ru"),
+        ignore = "needs the ru Language data (CRAFT_I18N_DIR; ru-extra.txt is embedded in every build that has it)"
+    )]
     #[test]
     fn supplement_words_decline() {
         for w in [
diff --git a/crates/proof/src/ru/mod.rs b/crates/proof/src/ru/mod.rs
index 17308da4..b88978af 100644
--- a/crates/proof/src/ru/mod.rs
+++ b/crates/proof/src/ru/mod.rs
@@ -363,7 +363,10 @@ mod tests {
         assert!(suggest::suggest_in(&none, "превет", 5).is_empty());
     }
 
-    #[cfg_attr(not(craft_proof_embed = "ru"), ignore = "needs the ru Language data (CRAFT_I18N_DIR, CRAFT_PROOF_EMBED=ru)")]
+    #[cfg_attr(
+        not(craft_proof_embed = "ru"),
+        ignore = "needs the ru Language data (CRAFT_I18N_DIR; ru-extra.txt is embedded in every build that has it)"
+    )]
     #[test]
     fn russian_words_are_correct() {
         test_dict::install();
diff --git a/crates/proof/src/vi.rs b/crates/proof/src/vi.rs
index cef4deb3..98a2db7e 100644
--- a/crates/proof/src/vi.rs
+++ b/crates/proof/src/vi.rs
@@ -76,6 +76,8 @@ mod checker_tests {
 
     #[test]
     fn vietnamese_paragraphs_under_english_get_no_marks() {
+        // English results depend on the dictionaries other tests install.
+        let _guard = crate::DICTIONARY_TESTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
         let text = "Hôm nay tôi đi học, trời rất đẹp và mát mẻ.";
         let spans = [(0..text.len(), ProofLang::En)];
         assert!(check_text_with(text, &spans, &Options::default(), true, false).is_empty());