diff --git includes/session.inc includes/session.inc
index ebba273..cba22f6 100644
--- includes/session.inc
+++ includes/session.inc
@@ -14,6 +14,23 @@ function sess_close() {
   return TRUE;
 }
 
+/**
+ * Reads an entire session from the database (internal use only).
+ *
+ * Also initializes the $user object for the user associated with the session.
+ * This function is registered with session_set_save_handler() to support
+ * database-backed sessions. It is called on every page load when PHP sets
+ * up the $_SESSION superglobal.
+ *
+ * This function should not be called directly. Session data should instead be
+ * accessed via the $_SESSION superglobal.
+ *
+ * @param $key
+ *   The session ID of the session to retrieve.
+ *
+ * @return
+ *   The user's session, or an empty string if no session exists.
+ */
 function sess_read($key) {
   global $user;
 
@@ -55,6 +72,23 @@ function sess_read($key) {
   return $user->session;
 }
 
+/**
+ * Writes an entire session to the database (internal use only).
+ *
+ * This function is registered with session_set_save_handler() to support
+ * database-backed sessions.
+ *
+ * This function should not be called directly. Session data should instead be
+ * accessed via the $_SESSION superglobal.
+ *
+ * @param $key
+ *   The session ID of the session to write to.
+ * @param $value
+ *   Session data to write as a serialized string.
+ *
+ * @return
+ *   Always returns TRUE.
+ */
 function sess_write($key, $value) {
   global $user;