diff --git a/hledger-lib/Hledger/Data/FormatStrings.hs b/hledger-lib/Hledger/Data/OutputFormat.hs
similarity index 87%
rename from hledger-lib/Hledger/Data/FormatStrings.hs
rename to hledger-lib/Hledger/Data/OutputFormat.hs
index 8bb04abe1..bd24cc4e9 100644
--- a/hledger-lib/Hledger/Data/FormatStrings.hs
+++ b/hledger-lib/Hledger/Data/OutputFormat.hs
@@ -1,8 +1,8 @@
-module Hledger.Data.FormatStrings (
-          parseFormatString
-        , formatStrings
+module Hledger.Data.OutputFormat (
+          parseStringFormat
+        , formatsp
         , formatValue
-        , FormatString(..)
+        , OutputFormat(..)
         , HledgerFormatField(..)
         , tests
         ) where
@@ -25,8 +25,8 @@ formatValue leftJustified min max value = printf formatS value
       max' = maybe "" (\i -> "." ++ (show i)) max
       formatS = "%" ++ l ++ min' ++ max' ++ "s"
 
-parseFormatString :: String -> Either String [FormatString]
-parseFormatString input = case (runParser formatStrings () "(unknown)") input of
+parseStringFormat :: String -> Either String [OutputFormat]
+parseStringFormat input = case (runParser formatsp () "(unknown)") input of
     Left y -> Left $ show y
     Right x -> Right x
 
@@ -43,7 +43,7 @@ field = do
     <|> try (string "total" >> return TotalField)
     <|> try (many1 digit >>= (\s -> return $ FieldNo $ read s))
 
-formatField :: GenParser Char st FormatString
+formatField :: GenParser Char st OutputFormat
 formatField = do
     char '%'
     leftJustified <- optionMaybe (char '-')
@@ -58,7 +58,7 @@ formatField = do
         Just text -> Just m where ((m,_):_) = readDec text
         _ -> Nothing
 
-formatLiteral :: GenParser Char st FormatString
+formatLiteral :: GenParser Char st OutputFormat
 formatLiteral = do
     s <- many1 c
     return $ FormatLiteral s
@@ -67,23 +67,23 @@ formatLiteral = do
       c =     (satisfy isPrintableButNotPercentage <?> "printable character")
           <|> try (string "%%" >> return '%')
 
-formatStr :: GenParser Char st FormatString
-formatStr =
+formatp :: GenParser Char st OutputFormat
+formatp =
         formatField
     <|> formatLiteral
 
-formatStrings :: GenParser Char st [FormatString]
-formatStrings = many formatStr
+formatsp :: GenParser Char st [OutputFormat]
+formatsp = many formatp
 
-testFormat :: FormatString -> String -> String -> Assertion
+testFormat :: OutputFormat -> String -> String -> Assertion
 testFormat fs value expected = assertEqual name expected actual
     where
         (name, actual) = case fs of
             FormatLiteral l -> ("literal", formatValue False Nothing Nothing l)
             FormatField leftJustify min max _ -> ("field", formatValue leftJustify min max value)
 
-testParser :: String -> [FormatString] -> Assertion
-testParser s expected = case (parseFormatString s) of
+testParser :: String -> [OutputFormat] -> Assertion
+testParser s expected = case (parseStringFormat s) of
     Left  error -> assertFailure $ show error
     Right actual -> assertEqual ("Input: " ++ s) expected actual
 
diff --git a/hledger-lib/Hledger/Data/Types.hs b/hledger-lib/Hledger/Data/Types.hs
index 271fbfdcc..a9bc53feb 100644
--- a/hledger-lib/Hledger/Data/Types.hs
+++ b/hledger-lib/Hledger/Data/Types.hs
@@ -195,7 +195,7 @@ data HledgerFormatField =
   | FieldNo Int
     deriving (Show, Eq)
 
-data FormatString =
+data OutputFormat =
     FormatLiteral String
   | FormatField Bool        -- Left justified ?
                 (Maybe Int) -- Min width
diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index b3df015f7..2c0390f2b 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -39,7 +39,7 @@ library
                   Hledger.Data.Amount
                   Hledger.Data.Commodity
                   Hledger.Data.Dates
-                  Hledger.Data.FormatStrings
+                  Hledger.Data.OutputFormat
                   Hledger.Data.Journal
                   Hledger.Data.Ledger
                   Hledger.Data.Posting
diff --git a/hledger/Hledger/Cli/Balance.hs b/hledger/Hledger/Cli/Balance.hs
index af24425be..4480ff040 100644
--- a/hledger/Hledger/Cli/Balance.hs
+++ b/hledger/Hledger/Cli/Balance.hs
@@ -250,7 +250,7 @@ import Text.Tabular.AsciiArt
 import Hledger
 import Prelude hiding (putStr)
 import Hledger.Utils.UTF8IOCompat (putStr)
-import Hledger.Data.FormatStrings
+import Hledger.Data.OutputFormat
 import Hledger.Cli.Options
 
 
@@ -309,7 +309,7 @@ This implementation turned out to be a bit convoluted but implements the followi
     b         USD -1  ; Account 'b' has two amounts. The account name is printed on the last line.
 -}
 -- | Render one balance report line item as plain text suitable for console output.
-balanceReportItemAsText :: ReportOpts -> [FormatString] -> BalanceReportItem -> [String]
+balanceReportItemAsText :: ReportOpts -> [OutputFormat] -> BalanceReportItem -> [String]
 balanceReportItemAsText opts format (_, accountName, depth, Mixed amounts) =
     -- 'amounts' could contain several quantities of the same commodity with different price.
     -- In order to combine them into single value (which is expected) we take the first price and
@@ -325,7 +325,7 @@ balanceReportItemAsText opts format (_, accountName, depth, Mixed amounts) =
       multiline [a]    = [formatBalanceReportItem opts (Just accountName) depth a format]
       multiline (a:as) = (formatBalanceReportItem opts Nothing depth a format) : multiline as
 
-formatBalanceReportItem :: ReportOpts -> Maybe AccountName -> Int -> Amount -> [FormatString] -> String
+formatBalanceReportItem :: ReportOpts -> Maybe AccountName -> Int -> Amount -> [OutputFormat] -> String
 formatBalanceReportItem _ _ _ _ [] = ""
 formatBalanceReportItem opts accountName depth amount (fmt:fmts) =
   s ++ (formatBalanceReportItem opts accountName depth amount fmts)
diff --git a/hledger/Hledger/Cli/Options.hs b/hledger/Hledger/Cli/Options.hs
index 1146ec2cf..82bd146c4 100644
--- a/hledger/Hledger/Cli/Options.hs
+++ b/hledger/Hledger/Cli/Options.hs
@@ -104,7 +104,7 @@ import Text.ParserCombinators.Parsec as P
 import Text.Printf
 
 import Hledger
-import Hledger.Data.FormatStrings as Format
+import Hledger.Data.OutputFormat as OutputFormat
 import Hledger.Cli.Version
 
 -- 
@@ -638,12 +638,12 @@ balancetypeopt rawopts
 
 -- | Parse the format option if provided, possibly returning an error,
 -- otherwise get the default value.
-formatFromOpts :: ReportOpts -> Either String [FormatString]
-formatFromOpts = maybe (Right defaultBalanceFormatString) parseFormatString . format_
+formatFromOpts :: ReportOpts -> Either String [OutputFormat]
+formatFromOpts = maybe (Right defaultBalanceFormat) parseStringFormat . format_
 
 -- | Default line format for balance report: "%20(total)  %2(depth_spacer)%-(account)"
-defaultBalanceFormatString :: [FormatString]
-defaultBalanceFormatString = [
+defaultBalanceFormat :: [OutputFormat]
+defaultBalanceFormat = [
       FormatField False (Just 20) Nothing TotalField
     , FormatLiteral "  "
     , FormatField True (Just 2) Nothing DepthSpacerField