mercurial/help/hgignore.txt

--- a/mercurial/help/hgignore.txt	Mon Apr 23 00:33:09 2012 +0900
+++ b/mercurial/help/hgignore.txt	Mon Apr 23 00:38:22 2012 +0900
@@ -63,6 +63,10 @@
 and a regexp pattern of the form ``\.c$`` will do the same. To root a
 regexp pattern, start it with ``^``.
 
+.. note::
+  Patterns specified in other than ``.hgignore`` are always rooted.
+  Please see :hg:`help patterns` for details.
+
 Example
 -------