diff --git a/mercurial/help/internals/wireprotocol.txt b/mercurial/help/internals/wireprotocol.txt
--- a/mercurial/help/internals/wireprotocol.txt
+++ b/mercurial/help/internals/wireprotocol.txt
@@ -662,6 +662,8 @@
 
 This command does not accept any arguments. Return type is a ``string``.
 
+This command was introduced in Mercurial 0.9.1 (released July 2006).
+
 changegroup
 -----------
 
@@ -779,6 +781,8 @@
 
 This command does not accept any arguments. The return type is a ``string``.
 
+This command was introduced in Mercurial 0.9.1 (released July 2006).
+
 listkeys
 --------