diff --git a/src/GF/CF/PPrCF.hs b/src/GF/CF/PPrCF.hs
index 11a710986..5f00e4b7e 100644
--- a/src/GF/CF/PPrCF.hs
+++ b/src/GF/CF/PPrCF.hs
@@ -50,9 +50,11 @@ prCFFun' profs (CFFun (t, p)) = prt_ t ++ pp p where
 prCFCat :: CFCat -> String
 prCFCat (CFCat (c,l)) = prt_ c ++ "-" ++ prt_ l ----
 
+prCFItem :: CFItem -> String
 prCFItem (CFNonterm c) = prCFCat c
 prCFItem (CFTerm a) = prRegExp a
 
+prRegExp :: RegExp -> String
 prRegExp (RegAlts tt) = case tt of
   [t] -> prQuotedString t
   _ -> prParenth (prTList " | " (map prQuotedString tt))
diff --git a/src/GF/Canon/MkGFC.hs b/src/GF/Canon/MkGFC.hs
index a1dfdbe2f..d1cf29e93 100644
--- a/src/GF/Canon/MkGFC.hs
+++ b/src/GF/Canon/MkGFC.hs
@@ -58,6 +58,7 @@ canon2grammar (Gr modules) = M.MGrammar $ map mod2info modules where
 grammar2canon :: CanonGrammar -> Canon
 grammar2canon (M.MGrammar modules) = Gr $ map info2mod modules 
 
+info2mod :: (Ident, M.ModInfo Ident Flag Info) -> Module
 info2mod m = case m of
     (a, M.ModMod (M.Module mt _ flags me os defs)) -> 
       let defs' = map info2def $ tree2list defs 
@@ -93,6 +94,7 @@ trCont cont = [(x,trExp t) | Decl x t <- cont]
 
 trFs = map trQIdent
 
+trExp :: Exp -> A.Term
 trExp t = case t of
   EProd x a b -> A.Prod x (trExp a) (trExp b)
   EAbs  x   b -> A.Abs  x (trExp b)
@@ -136,6 +138,7 @@ rtCont cont = [Decl (rtIdent x) (rtExp t) | (x,t) <- cont]
 
 rtFs = map rtQIdent
 
+rtExp :: A.Term -> Exp
 rtExp t = case t of
   A.Prod x a b -> EProd (rtIdent x) (rtExp a) (rtExp b)
   A.Abs  x   b -> EAbs  (rtIdent x) (rtExp b)
@@ -162,6 +165,7 @@ rtExp t = case t of
     _ -> error $ "MkGFC.rt not defined for" +++ show p
 
 
+rtQIdent :: (Ident, Ident) -> CIdent
 rtQIdent (m,c) = CIQ (rtIdent m) (rtIdent c)
 rtIdent x 
   | isWildIdent x = identC "h_" --- needed in declarations
diff --git a/src/GF/Data/Str.hs b/src/GF/Data/Str.hs
index 138c39f26..743d9edc9 100644
--- a/src/GF/Data/Str.hs
+++ b/src/GF/Data/Str.hs
@@ -102,6 +102,7 @@ isZeroTok t = case t of
 strTok :: Ss -> [(Ss,[String])] -> Str
 strTok ds vs = Str [TN ds vs]
 
+prStr :: Str -> String
 prStr = prQuotedString . sstr
 
 plusStr :: Str -> Str -> Str
diff --git a/src/GF/Data/Trie2.hs b/src/GF/Data/Trie2.hs
index 5f2d3de0a..08a6531be 100644
--- a/src/GF/Data/Trie2.hs
+++ b/src/GF/Data/Trie2.hs
@@ -30,6 +30,8 @@ newtype TrieT a b = TrieT ([(a,TrieT a b)],[b])
 newtype Trie a b = Trie (Map a (Trie a b), [b])
 
 emptyTrieT = TrieT ([],[])
+
+emptyTrie :: Trie a b
 emptyTrie = Trie (empty,[])
 
 optimize :: (Ord a,Eq b) => TrieT a b -> Trie a b
diff --git a/src/GF/Infra/ReadFiles.hs b/src/GF/Infra/ReadFiles.hs
index 8f6b5c971..7fd81386e 100644
--- a/src/GF/Infra/ReadFiles.hs
+++ b/src/GF/Infra/ReadFiles.hs
@@ -161,12 +161,19 @@ needCompile opts headers sfiles0 = paths $ res $ mark $ iter changed where
       CSRead -> gfcFile
       CSRes  -> gfrFile
 
+isGFC :: FilePath -> Bool
 isGFC = (== "gfc") . fileSuffix
 
+gfcFile :: FilePath -> FilePath
 gfcFile = suffixFile "gfc"
+
+gfrFile :: FilePath -> FilePath
 gfrFile = suffixFile "gfr"
+
+gfFile :: FilePath -> FilePath
 gfFile  = suffixFile "gf"
 
+resModName :: ModName -> ModName
 resModName = ('#':)
 
 -- to get imports without parsing the whole files
@@ -306,6 +313,7 @@ isOldFile f = do
 
 
 -- old GF tolerated newlines in quotes. No more supported!
+fixNewlines :: String -> String
 fixNewlines s = case s of
      '"':cs -> '"':mk cs
      c  :cs -> c:fixNewlines cs
diff --git a/src/GF/Text/Unicode.hs b/src/GF/Text/Unicode.hs
index 9039fbef0..e2775eb91 100644
--- a/src/GF/Text/Unicode.hs
+++ b/src/GF/Text/Unicode.hs
@@ -31,6 +31,7 @@ import ExtraDiacritics (mkExtraDiacritics)
 
 import Char
 
+mkUnicode :: String -> String
 mkUnicode s = case s of
   '/':'/':cs -> treat [] mkGreek   unic ++ mkUnicode rest
   '/':'+':cs -> mkHebrew  unic ++ mkUnicode rest
diff --git a/src/haddock/haddock-check.perl b/src/haddock/haddock-check.perl
index 57e311ed2..b65fbcc68 100644
--- a/src/haddock/haddock-check.perl
+++ b/src/haddock/haddock-check.perl
@@ -1,5 +1,11 @@
 
-# checking that a file is haddocky
+# checking that a file is haddocky:
+#   - checking if it has an export list
+#   - checking that all exported functions have type signatures
+#   - checking that the module header is OK
+
+# changes on files:
+#   - transforming hard space to ordinary space
 
 # limitations:
 #   - does not check that type aliases are put in the export list
@@ -8,6 +14,17 @@
 $operSym = qr/[\!\#\$\%\&\*\+\.\/\<\=\>\?\@\\\^\|\-\~\:]+/;
 $funSym = qr/[a-z]\w*\'*/;
 
+sub check_headerline {
+  my ($title, $regexp) = @_;
+  if (s/^-- $title *: +(.+?) *\n//s) {
+    $name = $1;
+    print "   > Incorrect ".lcfirst $title.": $name\n" unless $name =~ $regexp;
+  } else {
+    print "   > Header missing".lcfirst $title."\n";
+  }
+}
+
+
 for $file (@ARGV) {
   $file =~ s/\.hs//;
 
@@ -15,7 +32,22 @@ for $file (@ARGV) {
   $_ = join "", <F>;
   close F;
 
-  # print "- $file\n";
+  print "-- $file\n";
+
+  # the module header
+  s/^(--+\s*\n)+//s;
+  unless (s/^-- \|\s*\n//s) {
+    print "   > Incorrect module header\n";
+  } else {
+    &check_headerline("Module", qr/^[A-Z]\w*$/);
+    &check_headerline("Maintainer", qr/^[\wåäöÅÄÖüÜ\s\@\.]+$/);
+    &check_headerline("Stability", qr/.*/);
+    &check_headerline("Portability", qr/.*/);
+    s/^(--+\s*\n)+//s;
+    print "   > Missing CVS information\n" unless s/^(-- > CVS +\$.*?\$ *\n)+//s;
+    s/^(--+\s*\n)+//s;
+    print "   > Missing module description\n" unless /^-- +[^\(]/;
+  }
 
   # removing comments
   s/\{-.*?-\}//gs;
@@ -41,25 +73,25 @@ for $file (@ARGV) {
       $exportlist =~ s/\Q$function\E//;
     }
 
-    # type aliases
-    while (/\ntype\s+(\w+)/gs) {
-      $type = $1;
-      next if $exportlist =~ /\b$type\b/;
-      printf "%-30s | Type alias not in export list: %s\n", $file, $type;
-    }
-
     # exported functions without type signatures
     while ($exportlist =~ /(\b$funSym\b|\($operSym\))/gs) {
       $function = $1;
       # print "+ $function\n";
       next if $function =~ /^[A-Z]/;
       next if $function =~ /^\((\.\.|\:\:?|\=|\\|\||\<\-|\-\>|\@|\~|\=\>)\)$/;
-      printf "%-30s | No type signature for function: %s\n", $file, $function;
+      print "   > No type signature for function: $function\n";
     }
 
+    # type aliases
+    # while (/\ntype\s+(\w+)/gs) {
+    #   $type = $1;
+    #   next if $exportlist =~ /\b$type\b/;
+    #   printf "%-30s | Type alias not in export list: %s\n", $file, $type;
+    # }
+
   } else {
     # modules without export lists
-    printf "%-30s | No export list\n", $file;
+    print "   > No export list\n";
   }
 
 }
diff --git a/src/module-structure.txt b/src/module-structure.txt
index 678f47d28..31ececcc2 100644
--- a/src/module-structure.txt
+++ b/src/module-structure.txt
@@ -172,7 +172,7 @@ GF/
 		IncrementalChart
 		MCFGrammar		-> Grammar
 		MCFParserBasic
-		MCFRange
+		MCFRange                - obsolet
 		ParseCF
 		ParseCFG
 		ParseGFC