diff --git a/protocol-extensions.asciidoc b/protocol-extensions.asciidoc
index 6ffc1cb22..49a7cb44a 100644
--- a/protocol-extensions.asciidoc
+++ b/protocol-extensions.asciidoc
@@ -332,6 +332,7 @@ There are various problems with the current state of keyboard handling. They
 include:
 
   * No way to use modifiers other than `Ctrl` and `Alt`
+  * No way to use multiple modifier keys, other than, `Shift+Alt`.
   * No way to handle different types of keyboard events, such as press, release or repeat
   * No reliable way to distinguish single `Esc` keypresses from the 
     start of a escape sequence. Currently, client programs use