diff --git a/lib/linkheader.php b/lib/linkheader.php
index efa3f65ff3..a08fb67116 100644
--- a/lib/linkheader.php
+++ b/lib/linkheader.php
@@ -1,6 +1,51 @@
 <?php
 /**
- * @todo Add file header and documentation.
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2010, StatusNet, Inc.
+ *
+ * Parse HTTP response for interesting Link: headers
+ *
+ * PHP version 5
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Discovery
+ * @package   StatusNet
+ * @author    James Walker <james@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Class to represent Link: headers in an HTTP response
+ *
+ * Since these are a fairly important part of Hammer-stack discovery, they're
+ * reified and implemented here.
+ *
+ * @category  Discovery
+ * @package   StatusNet
+ * @author    James Walker <james@status.net>
+ * @copyright 2010 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
+ * @link      http://status.net/
+ *
+ * @see       Discovery
  */
 
 class LinkHeader
@@ -9,13 +54,21 @@ class LinkHeader
     var $rel;
     var $type;
 
+    /**
+     * Initialize from a string
+     *
+     * @param string $str Link: header value
+     *
+     * @return LinkHeader self
+     */
+
     function __construct($str)
     {
         preg_match('/^<[^>]+>/', $str, $uri_reference);
         //if (empty($uri_reference)) return;
 
         $this->href = trim($uri_reference[0], '<>');
-        $this->rel = array();
+        $this->rel  = array();
         $this->type = null;
 
         // remove uri-reference from header
@@ -25,9 +78,12 @@ class LinkHeader
         $params = explode(';', $str);
 
         foreach ($params as $param) {
-            if (empty($param)) continue;
+            if (empty($param)) { 
+                continue;
+            }
             list($param_name, $param_value) = explode('=', $param, 2);
-            $param_name = trim($param_name);
+
+            $param_name  = trim($param_name);
             $param_value = preg_replace('(^"|"$)', '', trim($param_value));
 
             // for now we only care about 'rel' and 'type' link params
@@ -43,6 +99,16 @@ class LinkHeader
         }
     }
 
+    /**
+     * Given an HTTP response, return the requested Link: header
+     *
+     * @param HTTP_Request2_Response $response response to check
+     * @param string                 $rel      relationship to look for
+     * @param string                 $type     media type to look for
+     *
+     * @return LinkHeader discovered header, or null on failure
+     */
+
     static function getLink($response, $rel=null, $type=null)
     {
         $headers = $response->getHeader('Link');