--- a/mercurial/commands.py	Fri Jan 11 16:51:54 2008 -0800
+++ b/mercurial/commands.py	Fri Jan 11 18:33:10 2008 -0800
@@ -388,6 +388,7 @@
 
     If no destination repository is specified the destination is assumed
     to have all the nodes specified by one or more --base parameters.
+    To create a bundle containing all changesets, use --base null.
 
     The bundle file can then be transferred using conventional means and
     applied to another repository with the unbundle or pull command.