diff --git a/library/HTMLPurifier/Doctype.php b/library/HTMLPurifier/Doctype.php
index 4056e569..4c9f3a05 100644
--- a/library/HTMLPurifier/Doctype.php
+++ b/library/HTMLPurifier/Doctype.php
@@ -11,11 +11,6 @@ class HTMLPurifier_Doctype
      */
     var $name;
     
-    /**
-     * List of aliases to doctype name
-     */
-    var $aliases = array();
-    
     /**
      * List of standard modules (string identifiers or literal objects)
      * that this doctype uses
@@ -28,6 +23,20 @@ class HTMLPurifier_Doctype
      * is enabled, such as lenient or correctional.
      */
     var $modulesForModes = array();
+    
+    /**
+     * List of aliases to doctype name
+     */
+    var $aliases = array();
+    
+    function HTMLPurifier_Doctype($name = null, $modules = array(),
+        $modules_for_modes = array(), $aliases = array()
+    ) {
+        $this->name = $name;
+        $this->modules = $modules;
+        $this->modulesForModes = $modules_for_modes;
+        $this->aliases = $aliases;
+    }
 }
 
 ?>
\ No newline at end of file
diff --git a/library/HTMLPurifier/DoctypeRegistry.php b/library/HTMLPurifier/DoctypeRegistry.php
new file mode 100644
index 00000000..8b3f0e0b
--- /dev/null
+++ b/library/HTMLPurifier/DoctypeRegistry.php
@@ -0,0 +1,69 @@
+<?php
+
+require_once 'HTMLPurifier/Doctype.php';
+
+class HTMLPurifier_DoctypeRegistry
+{
+    
+    /**
+     * Hash of doctype names to doctype objects
+     * @protected
+     */
+    var $doctypes;
+    
+    /**
+     * Lookup table of aliases to real doctype names
+     * @protected
+     */
+    var $aliases;
+    
+    /**
+     * Registers a doctype to the registry
+     * @note Accepts a fully-formed doctype object, or the
+     *       parameters for constructing a doctype object
+     * @param $doctype Name of doctype or literal doctype object
+     * @param $modules Modules doctype will load
+     * @param $modules_for_modes Modules doctype will load for certain modes
+     * @param $aliases Alias names for doctype
+     * @return Reference to registered doctype (usable for further editing)
+     */
+    function &register($doctype, $modules = array(),
+        $modules_for_modes = array(), $aliases = array()
+    ) {
+        if (!is_array($modules)) $modules = array($modules);
+        if (!is_array($aliases)) $aliases = array($aliases);
+        if (!is_object($doctype)) {
+            $doctype = new HTMLPurifier_Doctype(
+                $doctype, $modules, $modules_for_modes, $aliases
+            );
+        }
+        $this->doctypes[$doctype->name] =& $doctype;
+        $name = $doctype->name;
+        // hookup aliases
+        foreach ($doctype->aliases as $alias) {
+            if (isset($this->doctypes[$alias])) continue;
+            $this->aliases[$alias] = $name;
+        }
+        // remove old aliases
+        if (isset($this->aliases[$name])) unset($this->aliases[$name]);
+        return $doctype;
+    }
+    
+    /**
+     * Retrieves reference to a doctype of a certain name
+     * @note This function resolves aliases
+     * @param $doctype Name of doctype
+     * @return Reference to doctype object
+     */
+    function &get($doctype) {
+        if (isset($this->aliases[$doctype])) $doctype = $this->aliases[$doctype];
+        if (!isset($this->doctypes[$doctype])) {
+            trigger_error('Doctype ' . htmlspecialchars($doctype) . ' does not exist');
+            $null = null; return $null;
+        }
+        return $this->doctypes[$doctype];
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/HTMLPurifier/DoctypeRegistryTest.php b/tests/HTMLPurifier/DoctypeRegistryTest.php
new file mode 100644
index 00000000..b94b10e1
--- /dev/null
+++ b/tests/HTMLPurifier/DoctypeRegistryTest.php
@@ -0,0 +1,80 @@
+<?php
+
+require_once 'HTMLPurifier/DoctypeRegistry.php';
+
+class HTMLPurifier_DoctypeRegistryTest extends UnitTestCase
+{
+    
+    function test_register() {
+        
+        $registry = new HTMLPurifier_DoctypeRegistry();
+        
+        $d =& $registry->register(
+            $name = 'XHTML 1.0 Transitional',
+            $modules = array('module-one', 'module-two'),
+            $modulesForModes = array(
+                'lenient' => array('lenient-module'),
+            ),
+            $aliases = array('X10T')
+        );
+        
+        $d2 = new HTMLPurifier_Doctype($name, $modules, $modulesForModes, $aliases);
+        
+        $this->assertIdentical($d, $d2);
+        $this->assertReference($d, $registry->get('XHTML 1.0 Transitional'));
+        
+        // test shorthand
+        $d =& $registry->register(
+            $name = 'XHTML 1.0 Strict', 'module', array(), 'X10S'
+        );
+        $d2 = new HTMLPurifier_Doctype($name, array('module'), array(), array('X10S'));
+        
+        $this->assertIdentical($d, $d2);
+        
+    }
+    
+    function test_get() {
+        
+        // see also alias and register tests
+        
+        $registry = new HTMLPurifier_DoctypeRegistry();
+        
+        $this->expectError('Doctype XHTML 2.0 does not exist');
+        $registry->get('XHTML 2.0');
+        
+        // prevent XSS
+        $this->expectError('Doctype &lt;foo&gt; does not exist');
+        $registry->get('<foo>');
+        
+    }
+    
+    function testAliases() {
+        
+        $registry = new HTMLPurifier_DoctypeRegistry();
+        
+        $d1 =& $registry->register('Doc1', array(), array(), array('1'));
+        
+        $this->assertReference($d1, $registry->get('Doc1'));
+        $this->assertReference($d1, $registry->get('1'));
+        
+        $d2 =& $registry->register('Doc2', array(), array(), array('2'));
+        
+        $this->assertReference($d2, $registry->get('Doc2'));
+        $this->assertReference($d2, $registry->get('2'));
+        
+        $d3 =& $registry->register('1', array(), array(), array());
+        
+        // literal name overrides alias
+        $this->assertReference($d3, $registry->get('1'));
+        
+        $d4 =& $registry->register('One', array(), array(), array('1'));
+        
+        $this->assertReference($d4, $registry->get('One'));
+        // still it overrides
+        $this->assertReference($d3, $registry->get('1'));
+        
+    }
+    
+}
+
+?>
\ No newline at end of file
diff --git a/tests/test_files.php b/tests/test_files.php
index d0ec5089..602dc47b 100644
--- a/tests/test_files.php
+++ b/tests/test_files.php
@@ -55,6 +55,7 @@ $test_files[] = 'ChildDef/TableTest.php';
 $test_files[] = 'ConfigSchemaTest.php';
 $test_files[] = 'ConfigTest.php';
 $test_files[] = 'ContextTest.php';
+$test_files[] = 'DoctypeRegistryTest.php';
 $test_files[] = 'ElementDefTest.php';
 $test_files[] = 'EncoderTest.php';
 $test_files[] = 'EntityLookupTest.php';