diff --git a/library/HTMLPurifier.includes.php b/library/HTMLPurifier.includes.php
index e9916de0..97fcf27d 100644
--- a/library/HTMLPurifier.includes.php
+++ b/library/HTMLPurifier.includes.php
@@ -137,6 +137,7 @@ require 'HTMLPurifier/ConfigSchema/Validator/Alnum.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Composite.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Exists.php';
 require 'HTMLPurifier/ConfigSchema/Validator/NamespaceExists.php';
+require 'HTMLPurifier/ConfigSchema/Validator/Or.php';
 require 'HTMLPurifier/ConfigSchema/Validator/ParseId.php';
 require 'HTMLPurifier/ConfigSchema/Validator/ParseType.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Unique.php';
diff --git a/library/HTMLPurifier/ConfigSchema/Validator/Or.php b/library/HTMLPurifier/ConfigSchema/Validator/Or.php
new file mode 100644
index 00000000..fc818b64
--- /dev/null
+++ b/library/HTMLPurifier/ConfigSchema/Validator/Or.php
@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * Groups several validators together, but as an 'or': if the first
+ * one passes, we abort; if it throws an exception, we try the next validator,
+ * and the next. If all validators fail, we throw an exception.
+ *
+ * @note If no validators are registered, this validator automatically
+ *       "passes".
+ */
+class HTMLPurifier_ConfigSchema_Validator_Or extends HTMLPurifier_ConfigSchema_Validator
+{
+    
+    protected $validators = array();
+    
+    public function addValidator($validator) {
+        $this->validators[] = $validator;
+    }
+    
+    public function validate(&$arr, $interchange) {
+        $exceptions = array();
+        $pass = false;
+        foreach ($this->validators as $validator) {
+            try {
+                $validator->validate($arr, $interchange);
+            } catch (HTMLPurifier_ConfigSchema_Exception $e) {
+                $exceptions[] = $e;
+                continue;
+            }
+            $exceptions = array();
+            break;
+        }
+        if ($exceptions) {
+            // I wonder how we can make the exceptions "lossless"
+            throw new HTMLPurifier_ConfigSchema_Exception('All validators failed: ' . implode(";\n", $exceptions));
+        }
+    }
+    
+}
diff --git a/tests/HTMLPurifier/ConfigSchema/Validator/OrTest.php b/tests/HTMLPurifier/ConfigSchema/Validator/OrTest.php
new file mode 100644
index 00000000..d8718ff5
--- /dev/null
+++ b/tests/HTMLPurifier/ConfigSchema/Validator/OrTest.php
@@ -0,0 +1,31 @@
+<?php
+
+class HTMLPurifier_ConfigSchema_Validator_OrTest extends HTMLPurifier_ConfigSchema_ValidatorHarness
+{
+    
+    public function testValidatePass() {
+        $arr = array('ID' => 'RD');
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Alnum('ID'));
+        // Never called:
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('ALT-ID'));
+        $this->validator->validate($arr, $this->interchange);
+    }
+    
+    public function testValidatePassLater() {
+        $arr = array('ID' => 'RD');
+        // This one fails:
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('ALT-ID'));
+        // But this one passes:
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Alnum('ID'));
+        $this->validator->validate($arr, $this->interchange);
+    }
+    
+    public function testValidateFail() {
+        $arr = array('ID' => 'RD');
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('ALT-ID'));
+        $this->validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('FOOBAR'));
+        $this->expectException('HTMLPurifier_ConfigSchema_Exception');
+        $this->validator->validate($arr, $this->interchange);
+    }
+    
+}