diff -r a2a6fd1064df -r eb23c876c111 mercurial/commands.py
--- a/mercurial/commands.py	Mon Apr 19 11:31:19 2010 +0200
+++ b/mercurial/commands.py	Mon Apr 19 17:41:12 2010 +0900
@@ -3209,6 +3209,9 @@
     shared among repositories).
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
+
+    Since tag names have priority over branch names during revision
+    lookup, using an existing branch name as a tag name is discouraged.
     """
 
     rev_ = "."