diff --git a/.gitignore b/.gitignore
index 44e8ce9b0..005b72fc0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,3 +11,8 @@
 
 # Test data repo ignored. Please see instruction in tests-and-benchmarks.markdown
 /tests/text-test-data/
+
+# Data for case functions
+/scripts/CaseFolding.txt
+/scripts/SpecialCasing.txt
+/scripts/db-*.txt
diff --git a/cabal.tests.project b/cabal.tests.project
new file mode 100644
index 000000000..f6e611425
--- /dev/null
+++ b/cabal.tests.project
@@ -0,0 +1,5 @@
+-- this project doesn't have local 'text' package,
+-- so tests build faster.
+
+packages: tests
+tests: True
diff --git a/scripts/CaseFolding.hs b/scripts/CaseFolding.hs
index 11d180ca9..627482e26 100644
--- a/scripts/CaseFolding.hs
+++ b/scripts/CaseFolding.hs
@@ -12,6 +12,12 @@ module CaseFolding
 
 import Arsec
 
+import Data.Char (ord)
+import Data.Maybe (mapMaybe)
+import qualified Data.List as L
+import qualified Data.Set as Set
+import qualified Data.Map as Map
+
 data Fold = Fold {
       code :: Char
     , status :: Char
@@ -33,14 +39,104 @@ entries = CF <$> many comment <*> many (entry <* many comment)
 parseCF :: FilePath -> IO (Either ParseError CaseFolding)
 parseCF name = parse entries name <$> readFile name
 
-mapCF :: CaseFolding -> [String]
-mapCF (CF _ ms) = typ ++ (map nice . filter p $ ms) ++ [last]
+-- We generate mapping trying to call toLower
+mapCF :: [Map.Map Char (Char,Char,Char)] -> CaseFolding -> [String]
+mapCF dbs (CF _ ms) = concat
+    [ typ
+    , mapMaybe nice [ minBound .. maxBound ]
+    , [last]
+    ]
   where
+    -- characters for which base's toLower has different results
+    different :: Set.Set Char
+    different
+        = Map.keysSet
+        $ Map.filter g
+        $ L.foldl' (alignWith f) (Map.map ToChar dbh) dbt
+      where
+        dbh : dbt = map (Map.mapMaybeWithKey h) dbs
+
+        -- Only valid case is when both lhs and rhs of alignment
+        -- have the same single character.
+        -- Everything else is consider as different.
+        --
+        f :: These Maps Char -> Maps
+        f (This _)              = Differently
+        f (That _)              = Differently
+        f (These Differently _) = Differently
+        f (These (ToChar l) l')
+            | l == l'           = ToChar l
+            | otherwise         = Differently
+
+        -- We are only interested in Differently
+        -- for these we cannot trust toLower
+        g :: Maps -> Bool
+        g Differently = True
+        g (ToChar _)  = False
+
+        -- look for toLower data only
+        h c (_, l, _) | c == l    = Nothing
+                      | otherwise = Just l
+
+    -- we are only interested in C and F cases
+    -- * C: common case folding
+    -- * F: full case folding
+    --
+    -- Case Folding says
+    --
+    -- Usage:
+    --   A. To do a simple case folding, use the mappings with status C + S.
+    --   B. To do a full case folding, use the mappings with status C + F.
+    --
+    folds :: Map.Map Char Fold
+    folds = Map.fromList
+          $ map (\f -> (code f, f))
+          $ filter (\f -> status f `elem` "CF") ms
+
+    -- there are three cases:
+    --
+    nice :: Char -> Maybe String
+    nice c
+        -- not mapping to toLower, and toLower is same for all GHCs
+        | s /= [toLower c], not isDifferent
+        = Just
+        $ "-- " ++ n ++ "\n" ++
+          "foldMapping " ++ showC c ++ " s = Yield " ++ x ++ " (CC s " ++ y ++ " " ++ z ++ ")"
+
+        -- when toLower cannot be trusted
+        | isDifferent
+        = Just
+        $ "-- " ++ n ++ "\n" ++
+          "foldMapping " ++ showC c ++ " s = Yield " ++ x ++ " (CC s " ++ y ++ " " ++ z ++ ")"
+
+        -- otherwise omit, to be handled by catch all toLower case.
+        | otherwise
+        = Nothing
+      where
+        s :: [Char] -- mapping
+        n :: String -- name
+        (n, s) = maybe (defName, [c]) (\f -> (name f, mapping f)) (Map.lookup c folds)
+
+        isDifferent = Set.member c different
+
+        [x,y,z] = (map showC . take 3) (s ++ repeat '\0')
+
+        defName = "NOT FOLDED TO toLower " ++ showC c
+
     typ = ["foldMapping :: forall s. Char -> s -> Step (CC s) Char"
            ,"{-# NOINLINE foldMapping #-}"]
     last = "foldMapping c s = Yield (toLower c) (CC s '\\0' '\\0')"
-    nice c = "-- " ++ name c ++ "\n" ++
-             "foldMapping " ++ showC (code c) ++ " s = Yield " ++ x ++ " (CC s " ++ y ++ " " ++ z ++ ")"
-       where [x,y,z] = (map showC . take 3) (mapping c ++ repeat '\0')
-    p f = status f `elem` "CF" &&
-          mapping f /= [toLower (code f)]
+
+-- auxiliary data type used to determine whether toLower is the same for a char
+data Maps
+    = ToChar Char
+    | Differently
+  deriving Show
+
+alignWith :: Ord k => (These a b -> c) -> Map.Map k a -> Map.Map k b -> Map.Map k c
+alignWith f = Map.mergeWithKey
+    (\_ x y -> Just $ f $ These x y)
+    (Map.map (f . This))
+    (Map.map (f . That))
+
+data These a b = This a | That b | These a b deriving Show
diff --git a/scripts/CaseMapping.hs b/scripts/CaseMapping.hs
index e6350ab87..d8e721bb3 100644
--- a/scripts/CaseMapping.hs
+++ b/scripts/CaseMapping.hs
@@ -5,11 +5,23 @@ import Arsec
 import CaseFolding
 import SpecialCasing
 
+import qualified Data.Map as Map
+
+-- 1. download SpecialCasing.txt and CaseFolding.txt files from unicode.org
+--
+-- 2. dump Char DB by running dump.sh
+--
+-- 3. run from scripts/ directory with
+--
+--     runghc-8.6.5 -package-env=- CaseMapping.hs
+--
+
 main = do
   args <- getArgs
   let oname = case args of
-                [] -> "../Data/Text/Internal/Fusion/CaseMapping.hs"
+                [] -> "../src/Data/Text/Internal/Fusion/CaseMapping.hs"
                 [o] -> o
+  dbs <- loadDBs
   psc <- parseSC "SpecialCasing.txt"
   pcf <- parseCF "CaseFolding.txt"
   scs <- case psc of
@@ -34,5 +46,29 @@ main = do
   mapM_ (hPutStrLn h) (mapSC "upper" upper toUpper scs)
   mapM_ (hPutStrLn h) (mapSC "lower" lower toLower scs)
   mapM_ (hPutStrLn h) (mapSC "title" title toTitle scs)
-  mapM_ (hPutStrLn h) (mapCF cfs)
+  mapM_ (hPutStrLn h) (mapCF dbs cfs)
   hClose h
+
+loadDBs :: IO [Map.Map Char (Char,Char,Char)]
+loadDBs = mapM loadDB
+    [ "7.0.4"
+    , "7.2.2"
+    , "7.4.2"
+    , "7.6.3"
+    , "7.8.4"
+    , "7.10.3"
+
+    , "8.0.2"
+    , "8.2.2"
+    , "8.4.4"
+    , "8.6.5"
+    , "8.8.4"
+    , "8.10.2"
+
+    -- , "9.0.1"
+    ]
+  where
+    loadDB v = fmap (f . read) (readFile ("db-" ++ v ++ ".txt"))
+
+    f :: [(Char,Char,Char,Char)] -> Map.Map Char (Char,Char,Char)
+    f = Map.fromList . map (\(c,u,l,t) -> (c,(u,l,t)))
diff --git a/scripts/Dump.hs b/scripts/Dump.hs
new file mode 100644
index 000000000..a870e227a
--- /dev/null
+++ b/scripts/Dump.hs
@@ -0,0 +1,15 @@
+-- This script is used to dump casing DB from GHCs base library
+
+import Data.Char
+
+main :: IO ()
+main = print
+    [ (c, u, l, t)
+    | c <- [ minBound .. maxBound ]
+    , let u = toUpper c
+    , let l = toLower c
+    , let t = toTitle c
+
+    -- we dump only characters which have some transformations
+    , c /= u || c /= l || c /= t
+    ]
diff --git a/scripts/dump.sh b/scripts/dump.sh
new file mode 100644
index 000000000..4db5d145f
--- /dev/null
+++ b/scripts/dump.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+set -ex
+
+dump() {
+	"runghc-$1"  Dump.hs > "db-$1.txt"
+}
+
+dump 7.0.4
+dump 7.2.2
+dump 7.4.2
+dump 7.6.3
+dump 7.8.4
+dump 7.10.3
+
+dump 8.0.2
+dump 8.2.2
+dump 8.4.4
+dump 8.6.5
+dump 8.8.4
+dump 8.10.2
+
+# dump 9.0.1
diff --git a/scripts/tests.sh b/scripts/tests.sh
new file mode 100644
index 000000000..b3d6e87f9
--- /dev/null
+++ b/scripts/tests.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+set -ex
+
+runtest() {
+  HC=$1
+  shift
+
+  # EDIT last line to pass arguments
+
+  cabal run text-tests:test:tests \
+      --project-file=cabal.tests.project \
+      --builddir="dist-newstyle/$HC" \
+      --with-compiler="$HC" \
+      -- "$@"
+}
+
+runtest ghc-8.10.2 "$@"
+runtest ghc-8.8.4  "$@"
+runtest ghc-8.6.5  "$@"
+runtest ghc-8.4.4  "$@"
+runtest ghc-8.2.2  "$@"
+runtest ghc-8.0.2  "$@"
+
+runtest ghc-7.10.3 "$@"
+runtest ghc-7.8.4  "$@"
+runtest ghc-7.6.3  "$@"
+runtest ghc-7.4.2  "$@"
+runtest ghc-7.2.2  "$@"
+runtest ghc-7.0.4  "$@"
diff --git a/src/Data/Text/Internal/Fusion/CaseMapping.hs b/src/Data/Text/Internal/Fusion/CaseMapping.hs
index 0ea4f1a53..93944daed 100644
--- a/src/Data/Text/Internal/Fusion/CaseMapping.hs
+++ b/src/Data/Text/Internal/Fusion/CaseMapping.hs
@@ -1,10 +1,10 @@
 {-# LANGUAGE Rank2Types #-}
 -- AUTOMATICALLY GENERATED - DO NOT EDIT
 -- Generated by scripts/CaseMapping.hs
--- CaseFolding-9.0.0.txt
--- Date: 2016-03-02, 18:54:54 GMT
--- SpecialCasing-9.0.0.txt
--- Date: 2016-03-02, 18:55:13 GMT
+-- CaseFolding-13.0.0.txt
+-- Date: 2019-09-08, 23:30:59 GMT
+-- SpecialCasing-13.0.0.txt
+-- Date: 2019-09-08, 23:31:24 GMT
 
 module Data.Text.Internal.Fusion.CaseMapping where
 import Data.Char
@@ -337,6 +337,8 @@ foldMapping '\x017f' s = Yield '\x0073' (CC s '\x0000' '\x0000')
 foldMapping '\x01f0' s = Yield '\x006a' (CC s '\x030c' '\x0000')
 -- COMBINING GREEK YPOGEGRAMMENI
 foldMapping '\x0345' s = Yield '\x03b9' (CC s '\x0000' '\x0000')
+-- GREEK CAPITAL LETTER YOT
+foldMapping '\x037f' s = Yield '\x03f3' (CC s '\x0000' '\x0000')
 -- GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
 foldMapping '\x0390' s = Yield '\x03b9' (CC s '\x0308' '\x0301')
 -- GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
@@ -357,8 +359,196 @@ foldMapping '\x03f0' s = Yield '\x03ba' (CC s '\x0000' '\x0000')
 foldMapping '\x03f1' s = Yield '\x03c1' (CC s '\x0000' '\x0000')
 -- GREEK LUNATE EPSILON SYMBOL
 foldMapping '\x03f5' s = Yield '\x03b5' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER PE WITH DESCENDER
+foldMapping '\x0524' s = Yield '\x0525' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER SHHA WITH DESCENDER
+foldMapping '\x0526' s = Yield '\x0527' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER EN WITH LEFT HOOK
+foldMapping '\x0528' s = Yield '\x0529' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER DZZHE
+foldMapping '\x052a' s = Yield '\x052b' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER DCHE
+foldMapping '\x052c' s = Yield '\x052d' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER EL WITH DESCENDER
+foldMapping '\x052e' s = Yield '\x052f' (CC s '\x0000' '\x0000')
 -- ARMENIAN SMALL LIGATURE ECH YIWN
 foldMapping '\x0587' s = Yield '\x0565' (CC s '\x0582' '\x0000')
+-- GEORGIAN CAPITAL LETTER YN
+foldMapping '\x10c7' s = Yield '\x2d27' (CC s '\x0000' '\x0000')
+-- GEORGIAN CAPITAL LETTER AEN
+foldMapping '\x10cd' s = Yield '\x2d2d' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a0'
+foldMapping '\x13a0' s = Yield '\x13a0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a1'
+foldMapping '\x13a1' s = Yield '\x13a1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a2'
+foldMapping '\x13a2' s = Yield '\x13a2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a3'
+foldMapping '\x13a3' s = Yield '\x13a3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a4'
+foldMapping '\x13a4' s = Yield '\x13a4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a5'
+foldMapping '\x13a5' s = Yield '\x13a5' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a6'
+foldMapping '\x13a6' s = Yield '\x13a6' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a7'
+foldMapping '\x13a7' s = Yield '\x13a7' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a8'
+foldMapping '\x13a8' s = Yield '\x13a8' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13a9'
+foldMapping '\x13a9' s = Yield '\x13a9' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13aa'
+foldMapping '\x13aa' s = Yield '\x13aa' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ab'
+foldMapping '\x13ab' s = Yield '\x13ab' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ac'
+foldMapping '\x13ac' s = Yield '\x13ac' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ad'
+foldMapping '\x13ad' s = Yield '\x13ad' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ae'
+foldMapping '\x13ae' s = Yield '\x13ae' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13af'
+foldMapping '\x13af' s = Yield '\x13af' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b0'
+foldMapping '\x13b0' s = Yield '\x13b0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b1'
+foldMapping '\x13b1' s = Yield '\x13b1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b2'
+foldMapping '\x13b2' s = Yield '\x13b2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b3'
+foldMapping '\x13b3' s = Yield '\x13b3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b4'
+foldMapping '\x13b4' s = Yield '\x13b4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b5'
+foldMapping '\x13b5' s = Yield '\x13b5' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b6'
+foldMapping '\x13b6' s = Yield '\x13b6' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b7'
+foldMapping '\x13b7' s = Yield '\x13b7' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b8'
+foldMapping '\x13b8' s = Yield '\x13b8' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13b9'
+foldMapping '\x13b9' s = Yield '\x13b9' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ba'
+foldMapping '\x13ba' s = Yield '\x13ba' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13bb'
+foldMapping '\x13bb' s = Yield '\x13bb' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13bc'
+foldMapping '\x13bc' s = Yield '\x13bc' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13bd'
+foldMapping '\x13bd' s = Yield '\x13bd' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13be'
+foldMapping '\x13be' s = Yield '\x13be' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13bf'
+foldMapping '\x13bf' s = Yield '\x13bf' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c0'
+foldMapping '\x13c0' s = Yield '\x13c0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c1'
+foldMapping '\x13c1' s = Yield '\x13c1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c2'
+foldMapping '\x13c2' s = Yield '\x13c2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c3'
+foldMapping '\x13c3' s = Yield '\x13c3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c4'
+foldMapping '\x13c4' s = Yield '\x13c4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c5'
+foldMapping '\x13c5' s = Yield '\x13c5' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c6'
+foldMapping '\x13c6' s = Yield '\x13c6' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c7'
+foldMapping '\x13c7' s = Yield '\x13c7' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c8'
+foldMapping '\x13c8' s = Yield '\x13c8' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13c9'
+foldMapping '\x13c9' s = Yield '\x13c9' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ca'
+foldMapping '\x13ca' s = Yield '\x13ca' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13cb'
+foldMapping '\x13cb' s = Yield '\x13cb' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13cc'
+foldMapping '\x13cc' s = Yield '\x13cc' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13cd'
+foldMapping '\x13cd' s = Yield '\x13cd' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ce'
+foldMapping '\x13ce' s = Yield '\x13ce' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13cf'
+foldMapping '\x13cf' s = Yield '\x13cf' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d0'
+foldMapping '\x13d0' s = Yield '\x13d0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d1'
+foldMapping '\x13d1' s = Yield '\x13d1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d2'
+foldMapping '\x13d2' s = Yield '\x13d2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d3'
+foldMapping '\x13d3' s = Yield '\x13d3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d4'
+foldMapping '\x13d4' s = Yield '\x13d4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d5'
+foldMapping '\x13d5' s = Yield '\x13d5' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d6'
+foldMapping '\x13d6' s = Yield '\x13d6' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d7'
+foldMapping '\x13d7' s = Yield '\x13d7' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d8'
+foldMapping '\x13d8' s = Yield '\x13d8' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13d9'
+foldMapping '\x13d9' s = Yield '\x13d9' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13da'
+foldMapping '\x13da' s = Yield '\x13da' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13db'
+foldMapping '\x13db' s = Yield '\x13db' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13dc'
+foldMapping '\x13dc' s = Yield '\x13dc' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13dd'
+foldMapping '\x13dd' s = Yield '\x13dd' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13de'
+foldMapping '\x13de' s = Yield '\x13de' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13df'
+foldMapping '\x13df' s = Yield '\x13df' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e0'
+foldMapping '\x13e0' s = Yield '\x13e0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e1'
+foldMapping '\x13e1' s = Yield '\x13e1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e2'
+foldMapping '\x13e2' s = Yield '\x13e2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e3'
+foldMapping '\x13e3' s = Yield '\x13e3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e4'
+foldMapping '\x13e4' s = Yield '\x13e4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e5'
+foldMapping '\x13e5' s = Yield '\x13e5' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e6'
+foldMapping '\x13e6' s = Yield '\x13e6' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e7'
+foldMapping '\x13e7' s = Yield '\x13e7' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e8'
+foldMapping '\x13e8' s = Yield '\x13e8' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13e9'
+foldMapping '\x13e9' s = Yield '\x13e9' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ea'
+foldMapping '\x13ea' s = Yield '\x13ea' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13eb'
+foldMapping '\x13eb' s = Yield '\x13eb' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ec'
+foldMapping '\x13ec' s = Yield '\x13ec' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ed'
+foldMapping '\x13ed' s = Yield '\x13ed' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ee'
+foldMapping '\x13ee' s = Yield '\x13ee' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13ef'
+foldMapping '\x13ef' s = Yield '\x13ef' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f0'
+foldMapping '\x13f0' s = Yield '\x13f0' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f1'
+foldMapping '\x13f1' s = Yield '\x13f1' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f2'
+foldMapping '\x13f2' s = Yield '\x13f2' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f3'
+foldMapping '\x13f3' s = Yield '\x13f3' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f4'
+foldMapping '\x13f4' s = Yield '\x13f4' (CC s '\x0000' '\x0000')
+-- NOT FOLDED TO toLower '\x13f5'
+foldMapping '\x13f5' s = Yield '\x13f5' (CC s '\x0000' '\x0000')
 -- CHEROKEE SMALL LETTER YE
 foldMapping '\x13f8' s = Yield '\x13f0' (CC s '\x0000' '\x0000')
 -- CHEROKEE SMALL LETTER YI
@@ -389,6 +579,98 @@ foldMapping '\x1c86' s = Yield '\x044a' (CC s '\x0000' '\x0000')
 foldMapping '\x1c87' s = Yield '\x0463' (CC s '\x0000' '\x0000')
 -- CYRILLIC SMALL LETTER UNBLENDED UK
 foldMapping '\x1c88' s = Yield '\xa64b' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER AN
+foldMapping '\x1c90' s = Yield '\x10d0' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER BAN
+foldMapping '\x1c91' s = Yield '\x10d1' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER GAN
+foldMapping '\x1c92' s = Yield '\x10d2' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER DON
+foldMapping '\x1c93' s = Yield '\x10d3' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER EN
+foldMapping '\x1c94' s = Yield '\x10d4' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER VIN
+foldMapping '\x1c95' s = Yield '\x10d5' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER ZEN
+foldMapping '\x1c96' s = Yield '\x10d6' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER TAN
+foldMapping '\x1c97' s = Yield '\x10d7' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER IN
+foldMapping '\x1c98' s = Yield '\x10d8' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER KAN
+foldMapping '\x1c99' s = Yield '\x10d9' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER LAS
+foldMapping '\x1c9a' s = Yield '\x10da' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER MAN
+foldMapping '\x1c9b' s = Yield '\x10db' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER NAR
+foldMapping '\x1c9c' s = Yield '\x10dc' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER ON
+foldMapping '\x1c9d' s = Yield '\x10dd' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER PAR
+foldMapping '\x1c9e' s = Yield '\x10de' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER ZHAR
+foldMapping '\x1c9f' s = Yield '\x10df' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER RAE
+foldMapping '\x1ca0' s = Yield '\x10e0' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER SAN
+foldMapping '\x1ca1' s = Yield '\x10e1' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER TAR
+foldMapping '\x1ca2' s = Yield '\x10e2' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER UN
+foldMapping '\x1ca3' s = Yield '\x10e3' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER PHAR
+foldMapping '\x1ca4' s = Yield '\x10e4' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER KHAR
+foldMapping '\x1ca5' s = Yield '\x10e5' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER GHAN
+foldMapping '\x1ca6' s = Yield '\x10e6' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER QAR
+foldMapping '\x1ca7' s = Yield '\x10e7' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER SHIN
+foldMapping '\x1ca8' s = Yield '\x10e8' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER CHIN
+foldMapping '\x1ca9' s = Yield '\x10e9' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER CAN
+foldMapping '\x1caa' s = Yield '\x10ea' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER JIL
+foldMapping '\x1cab' s = Yield '\x10eb' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER CIL
+foldMapping '\x1cac' s = Yield '\x10ec' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER CHAR
+foldMapping '\x1cad' s = Yield '\x10ed' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER XAN
+foldMapping '\x1cae' s = Yield '\x10ee' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER JHAN
+foldMapping '\x1caf' s = Yield '\x10ef' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HAE
+foldMapping '\x1cb0' s = Yield '\x10f0' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HE
+foldMapping '\x1cb1' s = Yield '\x10f1' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HIE
+foldMapping '\x1cb2' s = Yield '\x10f2' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER WE
+foldMapping '\x1cb3' s = Yield '\x10f3' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HAR
+foldMapping '\x1cb4' s = Yield '\x10f4' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HOE
+foldMapping '\x1cb5' s = Yield '\x10f5' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER FI
+foldMapping '\x1cb6' s = Yield '\x10f6' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER YN
+foldMapping '\x1cb7' s = Yield '\x10f7' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER ELIFI
+foldMapping '\x1cb8' s = Yield '\x10f8' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER TURNED GAN
+foldMapping '\x1cb9' s = Yield '\x10f9' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER AIN
+foldMapping '\x1cba' s = Yield '\x10fa' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER AEN
+foldMapping '\x1cbd' s = Yield '\x10fd' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER HARD SIGN
+foldMapping '\x1cbe' s = Yield '\x10fe' (CC s '\x0000' '\x0000')
+-- GEORGIAN MTAVRULI CAPITAL LETTER LABIAL SIGN
+foldMapping '\x1cbf' s = Yield '\x10ff' (CC s '\x0000' '\x0000')
 -- LATIN SMALL LETTER H WITH LINE BELOW
 foldMapping '\x1e96' s = Yield '\x0068' (CC s '\x0331' '\x0000')
 -- LATIN SMALL LETTER T WITH DIAERESIS
@@ -563,8 +845,64 @@ foldMapping '\x1ff6' s = Yield '\x03c9' (CC s '\x0342' '\x0000')
 foldMapping '\x1ff7' s = Yield '\x03c9' (CC s '\x0342' '\x03b9')
 -- GREEK CAPITAL LETTER OMEGA WITH PROSGEGRAMMENI
 foldMapping '\x1ffc' s = Yield '\x03c9' (CC s '\x03b9' '\x0000')
+-- LATIN CAPITAL LETTER TURNED ALPHA
+foldMapping '\x2c70' s = Yield '\x0252' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER S WITH SWASH TAIL
+foldMapping '\x2c7e' s = Yield '\x023f' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER Z WITH SWASH TAIL
+foldMapping '\x2c7f' s = Yield '\x0240' (CC s '\x0000' '\x0000')
+-- COPTIC CAPITAL LETTER CRYPTOGRAMMIC SHEI
+foldMapping '\x2ceb' s = Yield '\x2cec' (CC s '\x0000' '\x0000')
+-- COPTIC CAPITAL LETTER CRYPTOGRAMMIC GANGIA
+foldMapping '\x2ced' s = Yield '\x2cee' (CC s '\x0000' '\x0000')
+-- COPTIC CAPITAL LETTER BOHAIRIC KHEI
+foldMapping '\x2cf2' s = Yield '\x2cf3' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER REVERSED TSE
+foldMapping '\xa660' s = Yield '\xa661' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER DOUBLE O
+foldMapping '\xa698' s = Yield '\xa699' (CC s '\x0000' '\x0000')
+-- CYRILLIC CAPITAL LETTER CROSSED O
+foldMapping '\xa69a' s = Yield '\xa69b' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER TURNED H
+foldMapping '\xa78d' s = Yield '\x0265' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER N WITH DESCENDER
+foldMapping '\xa790' s = Yield '\xa791' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER C WITH BAR
+foldMapping '\xa792' s = Yield '\xa793' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER B WITH FLOURISH
+foldMapping '\xa796' s = Yield '\xa797' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER F WITH STROKE
+foldMapping '\xa798' s = Yield '\xa799' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER VOLAPUK AE
+foldMapping '\xa79a' s = Yield '\xa79b' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER VOLAPUK OE
+foldMapping '\xa79c' s = Yield '\xa79d' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER VOLAPUK UE
+foldMapping '\xa79e' s = Yield '\xa79f' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER G WITH OBLIQUE STROKE
+foldMapping '\xa7a0' s = Yield '\xa7a1' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER K WITH OBLIQUE STROKE
+foldMapping '\xa7a2' s = Yield '\xa7a3' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER N WITH OBLIQUE STROKE
+foldMapping '\xa7a4' s = Yield '\xa7a5' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER R WITH OBLIQUE STROKE
+foldMapping '\xa7a6' s = Yield '\xa7a7' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER S WITH OBLIQUE STROKE
+foldMapping '\xa7a8' s = Yield '\xa7a9' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER H WITH HOOK
+foldMapping '\xa7aa' s = Yield '\x0266' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER REVERSED OPEN E
+foldMapping '\xa7ab' s = Yield '\x025c' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER SCRIPT G
+foldMapping '\xa7ac' s = Yield '\x0261' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER L WITH BELT
+foldMapping '\xa7ad' s = Yield '\x026c' (CC s '\x0000' '\x0000')
 -- LATIN CAPITAL LETTER SMALL CAPITAL I
 foldMapping '\xa7ae' s = Yield '\x026a' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER TURNED K
+foldMapping '\xa7b0' s = Yield '\x029e' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER TURNED T
+foldMapping '\xa7b1' s = Yield '\x0287' (CC s '\x0000' '\x0000')
 -- LATIN CAPITAL LETTER J WITH CROSSED-TAIL
 foldMapping '\xa7b2' s = Yield '\x029d' (CC s '\x0000' '\x0000')
 -- LATIN CAPITAL LETTER CHI
@@ -573,6 +911,28 @@ foldMapping '\xa7b3' s = Yield '\xab53' (CC s '\x0000' '\x0000')
 foldMapping '\xa7b4' s = Yield '\xa7b5' (CC s '\x0000' '\x0000')
 -- LATIN CAPITAL LETTER OMEGA
 foldMapping '\xa7b6' s = Yield '\xa7b7' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER U WITH STROKE
+foldMapping '\xa7b8' s = Yield '\xa7b9' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER GLOTTAL A
+foldMapping '\xa7ba' s = Yield '\xa7bb' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER GLOTTAL I
+foldMapping '\xa7bc' s = Yield '\xa7bd' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER GLOTTAL U
+foldMapping '\xa7be' s = Yield '\xa7bf' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER ANGLICANA W
+foldMapping '\xa7c2' s = Yield '\xa7c3' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER C WITH PALATAL HOOK
+foldMapping '\xa7c4' s = Yield '\xa794' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER S WITH HOOK
+foldMapping '\xa7c5' s = Yield '\x0282' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER Z WITH PALATAL HOOK
+foldMapping '\xa7c6' s = Yield '\x1d8e' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER D WITH SHORT STROKE OVERLAY
+foldMapping '\xa7c7' s = Yield '\xa7c8' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER S WITH SHORT STROKE OVERLAY
+foldMapping '\xa7c9' s = Yield '\xa7ca' (CC s '\x0000' '\x0000')
+-- LATIN CAPITAL LETTER REVERSED HALF H
+foldMapping '\xa7f5' s = Yield '\xa7f6' (CC s '\x0000' '\x0000')
 -- CHEROKEE SMALL LETTER A
 foldMapping '\xab70' s = Yield '\x13a0' (CC s '\x0000' '\x0000')
 -- CHEROKEE SMALL LETTER E
@@ -931,6 +1291,134 @@ foldMapping '\x10cb0' s = Yield '\x10cf0' (CC s '\x0000' '\x0000')
 foldMapping '\x10cb1' s = Yield '\x10cf1' (CC s '\x0000' '\x0000')
 -- OLD HUNGARIAN CAPITAL LETTER US
 foldMapping '\x10cb2' s = Yield '\x10cf2' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER NGAA
+foldMapping '\x118a0' s = Yield '\x118c0' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER A
+foldMapping '\x118a1' s = Yield '\x118c1' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER WI
+foldMapping '\x118a2' s = Yield '\x118c2' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER YU
+foldMapping '\x118a3' s = Yield '\x118c3' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER YA
+foldMapping '\x118a4' s = Yield '\x118c4' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER YO
+foldMapping '\x118a5' s = Yield '\x118c5' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER II
+foldMapping '\x118a6' s = Yield '\x118c6' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER UU
+foldMapping '\x118a7' s = Yield '\x118c7' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER E
+foldMapping '\x118a8' s = Yield '\x118c8' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER O
+foldMapping '\x118a9' s = Yield '\x118c9' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER ANG
+foldMapping '\x118aa' s = Yield '\x118ca' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER GA
+foldMapping '\x118ab' s = Yield '\x118cb' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER KO
+foldMapping '\x118ac' s = Yield '\x118cc' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER ENY
+foldMapping '\x118ad' s = Yield '\x118cd' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER YUJ
+foldMapping '\x118ae' s = Yield '\x118ce' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER UC
+foldMapping '\x118af' s = Yield '\x118cf' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER ENN
+foldMapping '\x118b0' s = Yield '\x118d0' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER ODD
+foldMapping '\x118b1' s = Yield '\x118d1' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER TTE
+foldMapping '\x118b2' s = Yield '\x118d2' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER NUNG
+foldMapping '\x118b3' s = Yield '\x118d3' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER DA
+foldMapping '\x118b4' s = Yield '\x118d4' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER AT
+foldMapping '\x118b5' s = Yield '\x118d5' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER AM
+foldMapping '\x118b6' s = Yield '\x118d6' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER BU
+foldMapping '\x118b7' s = Yield '\x118d7' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER PU
+foldMapping '\x118b8' s = Yield '\x118d8' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER HIYO
+foldMapping '\x118b9' s = Yield '\x118d9' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER HOLO
+foldMapping '\x118ba' s = Yield '\x118da' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER HORR
+foldMapping '\x118bb' s = Yield '\x118db' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER HAR
+foldMapping '\x118bc' s = Yield '\x118dc' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER SSUU
+foldMapping '\x118bd' s = Yield '\x118dd' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER SII
+foldMapping '\x118be' s = Yield '\x118de' (CC s '\x0000' '\x0000')
+-- WARANG CITI CAPITAL LETTER VIYO
+foldMapping '\x118bf' s = Yield '\x118df' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER M
+foldMapping '\x16e40' s = Yield '\x16e60' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER S
+foldMapping '\x16e41' s = Yield '\x16e61' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER V
+foldMapping '\x16e42' s = Yield '\x16e62' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER W
+foldMapping '\x16e43' s = Yield '\x16e63' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER ATIU
+foldMapping '\x16e44' s = Yield '\x16e64' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER Z
+foldMapping '\x16e45' s = Yield '\x16e65' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER KP
+foldMapping '\x16e46' s = Yield '\x16e66' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER P
+foldMapping '\x16e47' s = Yield '\x16e67' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER T
+foldMapping '\x16e48' s = Yield '\x16e68' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER G
+foldMapping '\x16e49' s = Yield '\x16e69' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER F
+foldMapping '\x16e4a' s = Yield '\x16e6a' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER I
+foldMapping '\x16e4b' s = Yield '\x16e6b' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER K
+foldMapping '\x16e4c' s = Yield '\x16e6c' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER A
+foldMapping '\x16e4d' s = Yield '\x16e6d' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER J
+foldMapping '\x16e4e' s = Yield '\x16e6e' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER E
+foldMapping '\x16e4f' s = Yield '\x16e6f' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER B
+foldMapping '\x16e50' s = Yield '\x16e70' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER C
+foldMapping '\x16e51' s = Yield '\x16e71' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER U
+foldMapping '\x16e52' s = Yield '\x16e72' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER YU
+foldMapping '\x16e53' s = Yield '\x16e73' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER L
+foldMapping '\x16e54' s = Yield '\x16e74' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER Q
+foldMapping '\x16e55' s = Yield '\x16e75' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER HP
+foldMapping '\x16e56' s = Yield '\x16e76' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER NY
+foldMapping '\x16e57' s = Yield '\x16e77' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER X
+foldMapping '\x16e58' s = Yield '\x16e78' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER D
+foldMapping '\x16e59' s = Yield '\x16e79' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER OE
+foldMapping '\x16e5a' s = Yield '\x16e7a' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER N
+foldMapping '\x16e5b' s = Yield '\x16e7b' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER R
+foldMapping '\x16e5c' s = Yield '\x16e7c' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER O
+foldMapping '\x16e5d' s = Yield '\x16e7d' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER AI
+foldMapping '\x16e5e' s = Yield '\x16e7e' (CC s '\x0000' '\x0000')
+-- MEDEFAIDRIN CAPITAL LETTER Y
+foldMapping '\x16e5f' s = Yield '\x16e7f' (CC s '\x0000' '\x0000')
 -- ADLAM CAPITAL LETTER ALIF
 foldMapping '\x1e900' s = Yield '\x1e922' (CC s '\x0000' '\x0000')
 -- ADLAM CAPITAL LETTER DAALI
diff --git a/tests-and-benchmarks.markdown b/tests-and-benchmarks.markdown
index 3e1e664c1..dd25eb6bf 100644
--- a/tests-and-benchmarks.markdown
+++ b/tests-and-benchmarks.markdown
@@ -1,6 +1,14 @@
 Tests and benchmarks
 ====================
 
+This file is most likely outdated. You can run tests by
+
+    cabal run text-tests:test:tests --project-file=cabal.tests.project --with-compiler ghc-8.6.5 --
+
+Or to run with all GHCs
+
+    sh scripts/tests.sh -- <arguments>
+
 Prerequisites
 -------------
 
diff --git a/tests/Tests/Properties.hs b/tests/Tests/Properties.hs
index 7b9db610b..d8b6e66c3 100644
--- a/tests/Tests/Properties.hs
+++ b/tests/Tests/Properties.hs
@@ -371,11 +371,15 @@ sf_toCaseFold_length p xs =
     where s = S.streamList xs
 t_toCaseFold_length t = T.length (T.toCaseFold t) >= T.length t
 tl_toCaseFold_length t = TL.length (TL.toCaseFold t) >= TL.length t
+t_toCaseFold_idempotent t = T.toCaseFold (T.toCaseFold t) == T.toCaseFold t
+tl_toCaseFold_idempotent t = TL.toCaseFold (TL.toCaseFold t) == TL.toCaseFold t
+
 t_toLower_length t = T.length (T.toLower t) >= T.length t
 t_toLower_lower t = p (T.toLower t) >= p t
     where p = T.length . T.filter isLower
 tl_toLower_lower t = p (TL.toLower t) >= p t
     where p = TL.length . TL.filter isLower
+
 t_toUpper_length t = T.length (T.toUpper t) >= T.length t
 t_toUpper_upper t = p (T.toUpper t) >= p t
     where p = T.length . T.filter isUpper
@@ -1118,6 +1122,8 @@ tests =
         testProperty "sf_toCaseFold_length" sf_toCaseFold_length,
         testProperty "t_toCaseFold_length" t_toCaseFold_length,
         testProperty "tl_toCaseFold_length" tl_toCaseFold_length,
+        testProperty "t_toCaseFold_idempotent" t_toCaseFold_idempotent,
+        testProperty "tl_toCaseFold_idempotent" tl_toCaseFold_idempotent,
         testProperty "t_toLower_length" t_toLower_length,
         testProperty "t_toLower_lower" t_toLower_lower,
         testProperty "tl_toLower_lower" tl_toLower_lower,
diff --git a/tests/Tests/Regressions.hs b/tests/Tests/Regressions.hs
index 8ff45b3cc..696098560 100644
--- a/tests/Tests/Regressions.hs
+++ b/tests/Tests/Regressions.hs
@@ -7,7 +7,9 @@ module Tests.Regressions
     ) where
 
 import Control.Exception (SomeException, handle)
-import Data.Char (isLetter)
+import Control.Monad (forM_)
+import Data.Char (isLetter, ord)
+import Numeric (showHex)
 import System.IO
 import Test.HUnit (assertBool, assertEqual, assertFailure)
 import qualified Data.ByteString as B
@@ -95,6 +97,15 @@ t227 =
                 (T.length $ T.filter isLetter $ T.take (-3) "Hello! How are you doing today?")
                 0
 
+t277 :: IO ()
+t277 =
+    forM_ [ c | c <- [ minBound .. maxBound ] ] $ \c -> do
+        let t = T.singleton c
+        assertEqual
+            ("toCaseFold should be idempotent: " ++ [c] ++ " 0x" ++ showHex (ord c) "")
+            (T.toCaseFold (T.toCaseFold t))
+            (T.toCaseFold t)
+
 tests :: F.Test
 tests = F.testGroup "Regressions"
     [ F.testCase "hGetContents_crash" hGetContents_crash
@@ -105,4 +116,5 @@ tests = F.testGroup "Regressions"
     , F.testCase "t197" t197
     , F.testCase "t221" t221
     , F.testCase "t227" t227
+    , F.testCase "t277" t277
     ]