diff --git a/Data/XML/DTD/Types.hs b/Data/XML/DTD/Types.hs
--- a/Data/XML/DTD/Types.hs
+++ b/Data/XML/DTD/Types.hs
@@ -149,7 +149,8 @@
 instance Typeable PEContent where
   typeOf = typeString "PEContent"
 
--- | A parameter entity reference
+-- | A parameter entity reference. It contains the name of the
+-- parameter entity that is being referenced.
 type PERef = Text
 
 -- | A declaration of an element.
diff --git a/dtd-types.cabal b/dtd-types.cabal
--- a/dtd-types.cabal
+++ b/dtd-types.cabal
@@ -1,5 +1,5 @@
 name: dtd-types
-version: 0.2.0.0
+version: 0.2.0.1
 synopsis: Basic types for representing XML DTDs
 description:
   This package provides types to represent an XML Document Type