diff --git a/fasta.cabal b/fasta.cabal
--- a/fasta.cabal
+++ b/fasta.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.7.2.0
+version:             0.7.2.1
 
 -- A short (one-line) description of the package.
 synopsis:            A simple, mindless parser for fasta files.
@@ -83,7 +83,7 @@
                        pipes-text >= 0.0 && < 0.1,
                        pipes-bytestring >= 2.1 && < 2.2,
                        lens >= 4.9 && < 4.12,
-                       foldl >= 1.0 && < 1.1
+                       foldl >= 1.0 && < 1.2
   
   -- Directories containing source files.
   hs-source-dirs:      src
diff --git a/src/Data/Fasta/ByteString/Lazy/Translation.hs b/src/Data/Fasta/ByteString/Lazy/Translation.hs
--- a/src/Data/Fasta/ByteString/Lazy/Translation.hs
+++ b/src/Data/Fasta/ByteString/Lazy/Translation.hs
@@ -30,6 +30,7 @@
 
 -- | Converts a codon to an amino acid
 -- Remember, if there is an "N" in that DNA sequence, then it is invalid
+-- and treated as a gap
 codon2aa :: Codon -> Either BL.ByteString BL.ByteString
 codon2aa x
     | codon `elem` ["GCT", "GCC", "GCA", "GCG"]               = Right "A"
@@ -63,8 +64,9 @@
     codon    = BL.map toUpper x
     errorMsg = BL.append "Unidentified codon: " codon
 
--- | Translates a string of nucleotides. Returns a text with the error if the
--- codon is invalid.
+-- | Translates a bytestring of nucleotides given a reading frame (1, 2, or
+-- 3) -- drops the first 0, 1, or 2 nucleotides respectively. Returns
+-- a bytestring with the error if the codon is invalid.
 translate :: Int64 -> FastaSequence -> Either BL.ByteString FastaSequence
 translate pos x
     | any isLeft' translation = Left $ head . lefts $ translation
diff --git a/src/Data/Fasta/ByteString/Translation.hs b/src/Data/Fasta/ByteString/Translation.hs
--- a/src/Data/Fasta/ByteString/Translation.hs
+++ b/src/Data/Fasta/ByteString/Translation.hs
@@ -29,6 +29,7 @@
 
 -- | Converts a codon to an amino acid
 -- Remember, if there is an "N" in that DNA sequence, then it is invalid
+-- and treated as a gap
 codon2aa :: Codon -> Either B.ByteString B.ByteString
 codon2aa x
     | codon `elem` ["GCT", "GCC", "GCA", "GCG"]               = Right "A"
@@ -62,8 +63,9 @@
     codon    = B.map toUpper x
     errorMsg = B.append "Unidentified codon: " codon
 
--- | Translates a string of nucleotides. Returns a text with the error if the
--- codon is invalid.
+-- | Translates a bytestring of nucleotides given a reading frame (1, 2, or
+-- 3) -- drops the first 0, 1, or 2 nucleotides respectively. Returns
+-- a bytestring with the error if the codon is invalid.
 translate :: Int -> FastaSequence -> Either B.ByteString FastaSequence
 translate pos x
     | any isLeft' translation = Left $ head . lefts $ translation
diff --git a/src/Data/Fasta/String/Translation.hs b/src/Data/Fasta/String/Translation.hs
--- a/src/Data/Fasta/String/Translation.hs
+++ b/src/Data/Fasta/String/Translation.hs
@@ -19,6 +19,7 @@
 
 -- | Converts a codon to an amino acid
 -- Remember, if there is an "N" in that DNA sequence, then it is invalid
+-- and treated as a gap
 codon2aa :: Codon -> Either String Char
 codon2aa x
     | codon `elem` ["GCT", "GCC", "GCA", "GCG"]               = Right 'A'
@@ -52,8 +53,9 @@
     codon    = map toUpper x
     errorMsg = "Unidentified codon: " ++ codon
 
--- | Translates a string of nucleotides. Returns a string with the error if the
--- codon is invalid.
+-- | Translates a string of nucleotides given a reading frame (1, 2, or
+-- 3) -- drops the first 0, 1, or 2 nucleotides respectively. Returns
+-- a string with the error if the codon is invalid.
 translate :: Int -> FastaSequence -> Either String FastaSequence
 translate pos x
     | any isLeft' translation = Left $ head . lefts $ translation
diff --git a/src/Data/Fasta/Text/Lazy/Translation.hs b/src/Data/Fasta/Text/Lazy/Translation.hs
--- a/src/Data/Fasta/Text/Lazy/Translation.hs
+++ b/src/Data/Fasta/Text/Lazy/Translation.hs
@@ -20,6 +20,7 @@
 
 -- | Converts a codon to an amino acid
 -- Remember, if there is an "N" in that DNA sequence, then it is invalid
+-- and treated as a gap
 codon2aa :: Codon -> Either T.Text T.Text
 codon2aa x
     | codon `elem` ["GCT", "GCC", "GCA", "GCG"]               = Right "A"
@@ -53,8 +54,9 @@
     codon    = T.toUpper x
     errorMsg = T.append "Unidentified codon: " codon
 
--- | Translates a string of nucleotides. Returns a text with the error if the
--- codon is invalid.
+-- | Translates a text of nucleotides given a reading frame (1, 2, or
+-- 3) -- drops the first 0, 1, or 2 nucleotides respectively. Returns
+-- a text with the error if the codon is invalid.
 translate :: Int64 -> FastaSequence -> Either T.Text FastaSequence
 translate pos x
     | any isLeft' translation = Left $ head . lefts $ translation
diff --git a/src/Data/Fasta/Text/Translation.hs b/src/Data/Fasta/Text/Translation.hs
--- a/src/Data/Fasta/Text/Translation.hs
+++ b/src/Data/Fasta/Text/Translation.hs
@@ -19,6 +19,7 @@
 
 -- | Converts a codon to an amino acid
 -- Remember, if there is an "N" in that DNA sequence, then it is invalid
+-- and treated as a gap
 codon2aa :: Codon -> Either T.Text T.Text
 codon2aa x
     | codon `elem` ["GCT", "GCC", "GCA", "GCG"]               = Right "A"
@@ -52,8 +53,9 @@
     codon    = T.toUpper x
     errorMsg = T.append "Unidentified codon: " codon
 
--- | Translates a string of nucleotides. Returns a text with the error if the
--- codon is invalid.
+-- | Translates a text of nucleotides given a reading frame (1, 2, or
+-- 3) -- drops the first 0, 1, or 2 nucleotides respectively. Returns
+-- a text with the error if the codon is invalid.
 translate :: Int -> FastaSequence -> Either T.Text FastaSequence
 translate pos x
     | any isLeft' translation = Left $ head . lefts $ translation