diff --git a/data/Default.hs b/data/Default.hs
--- a/data/Default.hs
+++ b/data/Default.hs
@@ -69,7 +69,12 @@
 error = last (sort x) ==> maximum x
 error = head (sortBy f x) ==> minimumBy f x
 error = last (sortBy f x) ==> maximumBy f x
+error "Avoid reverse" = reverse (sort x) ==> sortBy (flip compare) x
+error "Avoid reverse" = reverse (sortBy f x) ==> sortBy (flip f) x
+warn  = flip (g `on` h) ==> flip g `on` h
+warn  = (f `on` g) `on` h ==> f `on` (g . h)
 
+
 -- READ/SHOW
 
 error = showsPrec 0 x "" ==> show x
@@ -85,15 +90,23 @@
 warn "Use map once" = map f (map g x) ==> map (f . g) x
 warn  = x !! 0 ==> head x
 error = take n (repeat x) ==> replicate n x
+error = map f (replicate n x) ==> replicate n (f x)
+error = map f (repeat x) ==> repeat (f x)
 error = head (reverse x) ==> last x
 error = head (drop n x) ==> x !! n where _ = isNat n
 error = reverse (tail (reverse x)) ==> init x where note = IncreasesLaziness
+error "Avoid reverse" = reverse (reverse x) ==> x where note = IncreasesLaziness
 -- error = take (length x - 1) x ==> init x -- not true for x == []
 error = isPrefixOf (reverse x) (reverse y) ==> isSuffixOf x y
 error = foldr (++) [] ==> concat
 error = foldl (++) [] ==> concat where note = IncreasesLaziness
 error = span (not . p) ==> break p
 error = break (not . p) ==> span p
+error = (takeWhile p x, dropWhile p x) ==> span p x
+error = fst (span p x) ==> takeWhile p x
+error = snd (span p x) ==> dropWhile p x
+error = fst (break p x) ==> takeWhile (not . p) x
+error = snd (break p x) ==> dropWhile (not . p) x
 error = concatMap (++ "\n") ==> unlines
 error = map id ==> id
 error = or (map p x) ==> any p x
@@ -137,7 +150,6 @@
 warn "Use null" = length x >= 1 ==> not (null x) where note = IncreasesLaziness
 error "Take on a non-positive" = take i x ==> [] where _ = isNegZero i
 error "Drop on a non-positive" = drop i x ==> x where _ = isNegZero i
-error = (takeWhile p l, dropWhile p l) ==> span p l
 
 
 -- FOLDS
@@ -279,6 +291,8 @@
 error = sequence_ (zipWith f x y) ==> Control.Monad.zipWithM_ f x y
 error = sequence (replicate n x) ==> Control.Monad.replicateM n x
 error = sequence_ (replicate n x) ==> Control.Monad.replicateM_ n x
+error = mapM f (replicate n x) ==> Control.Monad.replicateM n (f x)
+error = mapM_ f (replicate n x) ==> Control.Monad.replicateM_ n (f x)
 error = mapM f (map g x) ==> mapM (f . g) x
 error = mapM_ f (map g x) ==> mapM_ (f . g) x
 error = mapM id ==> sequence
@@ -445,9 +459,12 @@
 
 -- COMPLEX
 
+{-
+-- these would be a good idea, but we have not yet proven them and they seem to have side conditions
 error "Use isPrefixOf" = take (length t) s == t ==> t `Data.List.isPrefixOf` s
 error "Use isPrefixOf" = (take i s == t) ==> _eval_ ((i >= length t) && (t `Data.List.isPrefixOf` s))
     where _ = (isList t || isLit t) && isPos i
+-}
 
 {-
 -- clever hint, but not actually a good idea
diff --git a/hlint.cabal b/hlint.cabal
--- a/hlint.cabal
+++ b/hlint.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.6
 build-type:         Simple
 name:               hlint
-version:            1.8.45
+version:            1.8.46
 license:            BSD3
 license-file:       LICENSE
 category:           Development
diff --git a/src/Settings.hs b/src/Settings.hs
--- a/src/Settings.hs
+++ b/src/Settings.hs
@@ -28,6 +28,7 @@
 getSeverity "warn" = Just Warning
 getSeverity "warning" = Just Warning
 getSeverity "error"  = Just Error
+getSeverity "hint"  = Just Error
 getSeverity _ = Nothing
 
 
@@ -147,6 +148,7 @@
 readSide :: [Decl_] -> (Maybe Exp_, [Note])
 readSide = foldl f (Nothing,[])
     where f (Nothing,notes) (PatBind _ PWildCard{} Nothing (UnGuardedRhs _ side) Nothing) = (Just side, notes)
+          f (Nothing,notes) (PatBind _ (fromNamed -> "side") Nothing (UnGuardedRhs _ side) Nothing) = (Just side, notes)
           f (side,[]) (PatBind _ (fromNamed -> "note") Nothing (UnGuardedRhs _ note) Nothing) = (side,g note)
           f _ x = errorOn x "bad side condition"