diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,3 +12,7 @@
 
 * First version revised B. Fixed another issue with being not compiled by the GHC-9.2 and higher.
 
+## 0.1.2.1 -- 2023-02-27
+
+* First version revised C. Some minor documentation improvements.
+
diff --git a/rhythmic-sequences.cabal b/rhythmic-sequences.cabal
--- a/rhythmic-sequences.cabal
+++ b/rhythmic-sequences.cabal
@@ -2,7 +2,7 @@
 name:               rhythmic-sequences
 
 -- The package version.
-version:            0.1.2.0
+version:            0.1.2.1
 
 -- A short (one-line) description of the package.
 synopsis:
diff --git a/src/Rhythmicity/MarkerSeqs.hs b/src/Rhythmicity/MarkerSeqs.hs
--- a/src/Rhythmicity/MarkerSeqs.hs
+++ b/src/Rhythmicity/MarkerSeqs.hs
@@ -43,7 +43,7 @@
 countWeightsQs :: (Foldable t) => [t a -> Int] -> [t a] -> [[Int]]
 countWeightsQs fs xs = map (flip map xs) fs
 
--- | Data type used to provide somewhat \'array sorting with its indeces\'.
+-- | Data type used to provide somewhat \'array sorting with its indices\'.
 data Sort2 a = S2 { 
  id :: Int8,
  val :: a
@@ -66,7 +66,7 @@
   show (S2 k x) = show k ++ '~':show x
 
 -- | Data type to contain the needed for hashing algorithm information about the sorted 
--- \'array sorting with its indeces\'.
+-- \'array sorting with its indices\'.
 data ASort3 a = As3 { 
  id3 :: Int8,
  orD :: Int8,
@@ -191,7 +191,7 @@
 idList :: Eq a => [Int8] -> [ASort3 a] -> [Int8]
 idList orDs ys = map (\(As3 k _ _) -> k) . filter (\(As3 _ n _) -> n `elem` orDs) $ ys
 
--- | Function to create bitwise representation of the intermediate date for the algorithm.
+-- | Function to create bitwise representation of the intermediate data for the algorithm.
 -- Should be very optimized to run fast.
 toNum :: [Int8] -> Integer
 toNum xs = foldl' setBit 0 . map fromEnum $ xs