diff --git a/doc/configuration.txt b/doc/configuration.txt
index 731158aa8..ddbe90a2c 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -26106,6 +26106,7 @@ Please refer to the table below for currently defined aliases :
   |   |      | HTTP/%[req.ver]                                      |         |
   +---+------+------------------------------------------------------+---------+
   |   | %ID  | unique-id                                            | string  |
+  |   |      | %[unique-id]                                         |         |
   +---+------+------------------------------------------------------+---------+
   |   | %ST  | status_code                                          | numeric |
   |   |      | %[txn.status]                                        |         |