diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+* 0.12.2 [2018-09-26]
+
+Add new parseQueryReplacePlus function, which allows specifying whether to replace '+' with ' '.
+
+Add header name constants for "Prefer" and "Preference-Applied" (RFC 7240).
+
 * 0.12.1 [2018-01-31]
 
 Add new functions for constructing a query URI where not all parts are escaped.
diff --git a/Network/HTTP/Types/Header.hs b/Network/HTTP/Types/Header.hs
--- a/Network/HTTP/Types/Header.hs
+++ b/Network/HTTP/Types/Header.hs
@@ -40,6 +40,8 @@
 , hMaxForwards
 , hOrigin
 , hPragma
+, hPrefer
+, hPreferenceApplied
 , hProxyAuthenticate
 , hProxyAuthorization
 , hRange
@@ -158,6 +160,11 @@
 -- | HTTP Header names according to https://tools.ietf.org/html/rfc6454
 hOrigin :: HeaderName
 hOrigin = "Origin"
+
+-- | HTTP Header names according to https://tools.ietf.org/html/rfc7240
+hPrefer, hPreferenceApplied :: HeaderName
+hPrefer = "Prefer"
+hPreferenceApplied = "Preference-Applied"
 
 -- | RFC 2616 Byte range (individual).
 --
diff --git a/Network/HTTP/Types/URI.hs b/Network/HTTP/Types/URI.hs
--- a/Network/HTTP/Types/URI.hs
+++ b/Network/HTTP/Types/URI.hs
@@ -11,6 +11,7 @@
 , renderQueryBuilder
 , renderSimpleQuery
 , parseQuery
+, parseQueryReplacePlus
 , parseSimpleQuery
   -- **Escape only parts
 , renderQueryPartialEscape
@@ -61,8 +62,8 @@
 
 -- | Query.
 -- 
--- General form: a=b&c=d, but if the value is Nothing, it becomes
--- a&c=d.
+-- General form: @a=b&c=d@, but if the value is Nothing, it becomes
+-- @a&c=d@.
 type Query = [QueryItem]
 
 -- | Like Query, but with 'Text' instead of 'B.ByteString' (UTF8-encoded).
@@ -137,10 +138,17 @@
 -- decoding here. Most likely, you will want to use UTF-8 decoding, but this is
 -- left to the user of the library.
 -- 
--- * Percent decoding errors are ignored. In particular, "%Q" will be output as
--- "%Q".
+-- * Percent decoding errors are ignored. In particular, @"%Q"@ will be output as
+-- @"%Q"@.
+--
+-- * It decodes @\'+\'@ characters to @\' \'@
 parseQuery :: B.ByteString -> Query
-parseQuery = parseQueryString' . dropQuestion
+parseQuery = parseQueryReplacePlus True
+
+-- | Same functionality as 'parseQuery' with the option to decode @\'+\'@ characters to @\' \'@
+-- or preserve @\'+\'@
+parseQueryReplacePlus :: Bool -> B.ByteString -> Query
+parseQueryReplacePlus replacePlus bs = parseQueryString' $ dropQuestion bs
   where
     dropQuestion q =
         case B.uncons q of
@@ -155,9 +163,9 @@
             let (k, v) = B.break (== 61) x -- equal sign
                 v'' =
                     case B.uncons v of
-                        Just (_, v') -> Just $ urlDecode True v'
+                        Just (_, v') -> Just $ urlDecode replacePlus v'
                         _ -> Nothing
-             in (urlDecode True k, v'')
+             in (urlDecode replacePlus k, v'')
 
 queryStringSeparators :: B.ByteString
 queryStringSeparators = B.pack [38,59] -- ampersand, semicolon
@@ -207,13 +215,13 @@
 urlEncodeBuilder False = urlEncodeBuilder' unreservedPI
 
 -- | Percent-encoding for URLs.
-urlEncode :: Bool -- ^ Whether to decode '+' to ' '
+urlEncode :: Bool -- ^ Whether to decode @\'+\'@ to @\' \'@
           -> B.ByteString -- ^ The ByteString to encode as URL
           -> B.ByteString -- ^ The encoded URL
 urlEncode q = BL.toStrict . B.toLazyByteString . urlEncodeBuilder q
 
 -- | Percent-decoding.
-urlDecode :: Bool -- ^ Whether to decode '+' to ' '
+urlDecode :: Bool -- ^ Whether to decode @\'+\'@ to @\' \'@
           -> B.ByteString -> B.ByteString
 urlDecode replacePlus z = fst $ B.unfoldrN (B.length z) go z
   where
@@ -242,22 +250,19 @@
 -- 
 -- * UTF-8 encodes the characters.
 -- 
--- * Performs percent encoding on all unreserved characters, as well as \:\@\=\+\$,
+-- * Performs percent encoding on all unreserved characters, as well as @\:\@\=\+\$@,
 -- 
 -- * Prepends each segment with a slash.
 -- 
 -- For example:
 -- 
 -- > encodePathSegments [\"foo\", \"bar\", \"baz\"]
--- 
 -- \"\/foo\/bar\/baz\"
 -- 
 -- > encodePathSegments [\"foo bar\", \"baz\/bin\"]
--- 
 -- \"\/foo\%20bar\/baz\%2Fbin\"
 -- 
 -- > encodePathSegments [\"שלום\"]
--- 
 -- \"\/%D7%A9%D7%9C%D7%95%D7%9D\"
 -- 
 -- Huge thanks to Jeremy Shaw who created the original implementation of this
@@ -333,12 +338,12 @@
 -----------------------------------------------------------------------------------------
 
 -- | For some URIs characters must not be URI encoded,
--- eg '+' or ':' in q=a+language:haskell+created:2009-01-01..2009-02-01&sort=stars
+-- e.g. @\'+\'@ or @\':\'@ in @q=a+language:haskell+created:2009-01-01..2009-02-01&sort=stars@
 -- The character list unreservedPI instead of unreservedQS would solve this.
 -- But we explicitly decide what part to encode.
--- This is mandatory when searching for '+': q=%2B+language:haskell.
+-- This is mandatory when searching for @\'+\'@: @q=%2B+language:haskell@.
 data EscapeItem = QE B.ByteString -- will be URL encoded
-                | QN B.ByteString -- will not be url encoded, eg '+' or ':'
+                | QN B.ByteString -- will not be url encoded, e.g. @\'+\'@ or @\':\'@
     deriving (Show, Eq, Ord)
 
 -- | Query item
@@ -346,7 +351,7 @@
 
 -- | Query with some chars that should not be escaped.
 -- 
--- General form: a=b&c=d:e+f&g=h
+-- General form: @a=b&c=d:e+f&g=h@
 type PartialEscapeQuery = [PartialEscapeQueryItem]
 
 -- | Convert 'PartialEscapeQuery' to 'ByteString'.
diff --git a/http-types.cabal b/http-types.cabal
--- a/http-types.cabal
+++ b/http-types.cabal
@@ -1,5 +1,5 @@
 Name:                http-types
-Version:             0.12.1
+Version:             0.12.2
 Synopsis:            Generic HTTP types for Haskell (for both client and server code).
 Description:         Generic HTTP types for Haskell (for both client and server code).
 Homepage:            https://github.com/aristidb/http-types
@@ -16,7 +16,7 @@
 Source-repository this
   type: git
   location: https://github.com/aristidb/http-types.git
-  tag: 0.12.1
+  tag: 0.12.2
 
 Source-repository head
   type: git