diff --git a/library/HTMLPurifier/AttrDef/Length.php b/library/HTMLPurifier/AttrDef/Length.php
new file mode 100644
index 00000000..7cddb67d
--- /dev/null
+++ b/library/HTMLPurifier/AttrDef/Length.php
@@ -0,0 +1,37 @@
+<?php
+
+require_once 'HTMLPurifier/AttrDef.php';
+require_once 'HTMLPurifier/AttrDef/Pixels.php';
+
+class HTMLPurifier_AttrDef_Length extends HTMLPurifier_AttrDef_Pixels
+{
+    
+    function validate($string) {
+        
+        $string = trim($string);
+        if ($string === '') return false;
+        
+        $parent_result = parent::validate($string);
+        if ($parent_result !== false) return $parent_result;
+        
+        $length = strlen($string);
+        $last_char = $string[$length - 1];
+        
+        if ($last_char !== '%') return false;
+        
+        $points = substr($string, 0, $length - 1);
+        
+        if (!is_numeric($points)) return false;
+        
+        $points = (int) $points;
+        
+        if ($points < 0) return '0%';
+        if ($points > 100) return '100%';
+        
+        return ((string) $points) . '%';
+        
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/Definition.php b/library/HTMLPurifier/Definition.php
index 0fe46332..a8766927 100644
--- a/library/HTMLPurifier/Definition.php
+++ b/library/HTMLPurifier/Definition.php
@@ -7,6 +7,7 @@ require_once 'HTMLPurifier/AttrDef.php';
     require_once 'HTMLPurifier/AttrDef/Text.php';
     require_once 'HTMLPurifier/AttrDef/Lang.php';
     require_once 'HTMLPurifier/AttrDef/Pixels.php';
+    require_once 'HTMLPurifier/AttrDef/Length.php';
 require_once 'HTMLPurifier/AttrTransform.php';
     require_once 'HTMLPurifier/AttrTransform/Lang.php';
     require_once 'HTMLPurifier/AttrTransform/TextAlign.php';
@@ -243,10 +244,6 @@ class HTMLPurifier_Definition
         // complex attribute value substitution
         
         $e_Text = new HTMLPurifier_AttrDef_Text();
-        $e_TFrame = new HTMLPurifier_AttrDef_Enum(array('void', 'above',
-            'below', 'hsides', 'lhs', 'rhs', 'vsides', 'box', 'border'), false);
-        $e_TRules = new HTMLPurifier_AttrDef_Enum(array('none', 'groups',
-            'rows', 'cols', 'all'), false);
         
         // attrs, included in almost every single one except for a few,
         // which manually override these in their local definitions
@@ -271,34 +268,34 @@ class HTMLPurifier_Definition
         $this->info['td']->attr['abbr'] = $e_Text;
         $this->info['th']->attr['abbr'] = $e_Text;
         
-        $this->info['col']->attr['align'] = 
-        $this->info['colgroup']->attr['align'] = 
-        $this->info['tbody']->attr['align'] = 
-        $this->info['td']->attr['align'] = 
-        $this->info['tfoot']->attr['align'] = 
-        $this->info['th']->attr['align'] = 
-        $this->info['thead']->attr['align'] = 
-        $this->info['tr']->attr['align'] = new HTMLPurifier_AttrDef_Enum(
-            array('left', 'center', 'right', 'justify', 'char'), false);
+        $this->setAttrForTableElements('align', new HTMLPurifier_AttrDef_Enum(
+            array('left', 'center', 'right', 'justify', 'char'), false));
         
-        $this->info['col']->attr['valign'] = 
-        $this->info['colgroup']->attr['valign'] = 
-        $this->info['tbody']->attr['valign'] = 
-        $this->info['td']->attr['valign'] = 
-        $this->info['tfoot']->attr['valign'] = 
-        $this->info['th']->attr['valign'] = 
-        $this->info['thead']->attr['valign'] = 
-        $this->info['tr']->attr['valign'] = new HTMLPurifier_AttrDef_Enum(
-            array('top', 'middle', 'bottom', 'baseline'), false);
+        $this->setAttrForTableElements('valign', new HTMLPurifier_AttrDef_Enum(
+            array('top', 'middle', 'bottom', 'baseline'), false));
         
         $this->info['img']->attr['alt'] = $e_Text;
         
+        $e_TFrame = new HTMLPurifier_AttrDef_Enum(array('void', 'above',
+            'below', 'hsides', 'lhs', 'rhs', 'vsides', 'box', 'border'), false);
         $this->info['table']->attr['frame'] = $e_TFrame;
+        
+        $e_TRules = new HTMLPurifier_AttrDef_Enum(array('none', 'groups',
+            'rows', 'cols', 'all'), false);
         $this->info['table']->attr['rules'] = $e_TRules;
+        
         $this->info['table']->attr['summary'] = $e_Text;
         
         $this->info['table']->attr['border'] = new HTMLPurifier_AttrDef_Pixels();
         
+        $e_Length = new HTMLPurifier_AttrDef_Length();
+        $this->info['table']->attr['cellpadding'] = $e_Length;
+        $this->info['table']->attr['cellspacing'] = $e_Length;
+        $this->info['table']->attr['width'] = $e_Length;
+        $this->setAttrForTableElements('charoff', $e_Length);
+        $this->info['img']->attr['height'] = $e_Length;
+        $this->info['img']->attr['width'] = $e_Length;
+        
         //////////////////////////////////////////////////////////////////////
         // UNIMP : info_tag_transform : transformations of tags
         
@@ -346,6 +343,17 @@ class HTMLPurifier_Definition
         
     }
     
+    function setAttrForTableElements($attr, $def) {
+        $this->info['col']->attr[$attr] = 
+        $this->info['colgroup']->attr[$attr] = 
+        $this->info['tbody']->attr[$attr] = 
+        $this->info['td']->attr[$attr] = 
+        $this->info['tfoot']->attr[$attr] = 
+        $this->info['th']->attr[$attr] = 
+        $this->info['thead']->attr[$attr] = 
+        $this->info['tr']->attr[$attr] = $def;
+    }
+    
 }
 
 class HTMLPurifier_ElementDef
diff --git a/tests/HTMLPurifier/AttrDef/LengthTest.php b/tests/HTMLPurifier/AttrDef/LengthTest.php
new file mode 100644
index 00000000..724cda58
--- /dev/null
+++ b/tests/HTMLPurifier/AttrDef/LengthTest.php
@@ -0,0 +1,35 @@
+<?php
+
+require_once 'HTMLPurifier/AttrDefHarness.php';
+require_once 'HTMLPurifier/AttrDef/Length.php';
+
+class HTMLPurifier_AttrDef_LengthTest extends HTMLPurifier_AttrDef_PixelsTest
+{
+    
+    function setup() {
+        $this->def = new HTMLPurifier_AttrDef_Length();
+    }
+    
+    function test() {
+        
+        // pixel check
+        parent::test();
+        
+        // percent check
+        $this->assertDef('25%');
+        
+        // Firefox maintains percent, so will we
+        $this->assertDef('0%');
+        
+        // 0% <= percent <= 100%
+        $this->assertDef('-15%', '0%');
+        $this->assertDef('120%', '100%');
+        
+        // fractional percents, apparently, aren't allowed
+        $this->assertDef('56.5%', '56%');
+        
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/AttrDef/PixelsTest.php b/tests/HTMLPurifier/AttrDef/PixelsTest.php
index ad62235b..cab43e86 100644
--- a/tests/HTMLPurifier/AttrDef/PixelsTest.php
+++ b/tests/HTMLPurifier/AttrDef/PixelsTest.php
@@ -6,9 +6,11 @@ require_once 'HTMLPurifier/AttrDef/Pixels.php';
 class HTMLPurifier_AttrDef_PixelsTest extends HTMLPurifier_AttrDefHarness
 {
     
-    function test() {
-        
+    function setup() {
         $this->def = new HTMLPurifier_AttrDef_Pixels();
+    }
+    
+    function test() {
         
         $this->assertDef('1');
         $this->assertDef('0');
diff --git a/tests/HTMLPurifier/Strategy/ValidateAttributesTest.php b/tests/HTMLPurifier/Strategy/ValidateAttributesTest.php
index 17d6ba08..5b8650cb 100644
--- a/tests/HTMLPurifier/Strategy/ValidateAttributesTest.php
+++ b/tests/HTMLPurifier/Strategy/ValidateAttributesTest.php
@@ -69,12 +69,16 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
         
         // test table
         $inputs[13] = <<<HTML
-<table frame="above" rules="rows" summary="A test table" border="2">
+<table frame="above" rules="rows" summary="A test table" border="2" cellpadding="5%" cellspacing="3" width="100%">
+    <col align="right" />
+    <col charoff="5" align="char" />
     <tr valign="top">
-        <th abbr="super" align="left">Supercalifragilistic</th>
+        <th abbr="name">Fiddly name</th>
+        <th abbr="price">Super-duper-price</th>
     </tr>
     <tr>
-        <td abbr="one">Cell one</td>
+        <td abbr="carrot">Carrot Humungous</td>
+        <td>$500.23</td>
     </tr>
 </table>
 HTML;
diff --git a/tests/index.php b/tests/index.php
index a7ee1e2b..fc326706 100644
--- a/tests/index.php
+++ b/tests/index.php
@@ -44,6 +44,7 @@ $test_files[] = 'AttrDef/ClassTest.php';
 $test_files[] = 'AttrDef/TextTest.php';
 $test_files[] = 'AttrDef/LangTest.php';
 $test_files[] = 'AttrDef/PixelsTest.php';
+$test_files[] = 'AttrDef/LengthTest.php';
 $test_files[] = 'IDAccumulatorTest.php';
 $test_files[] = 'TagTransformTest.php';
 $test_files[] = 'AttrTransform/LangTest.php';