update doc.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10487 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/pathname.rb b/lib/pathname.rb
index 7eaa82b7ce..e4ca5489ce 100644
--- a/lib/pathname.rb
+++ b/lib/pathname.rb
@@ -15,6 +15,10 @@
 # == Pathname
 #
 # Pathname represents a pathname which locates a file in a filesystem.
+# The pathname depends on OS: Unix, Windows, etc.
+# Pathname library works with pathnames of local OS.
+# However non-Unix pathnames are supported experimentally.
+#
 # It does not represent the file itself.
 # A Pathname can be relative or absolute.  It's not until you try to
 # reference the file that it even matters whether the file exists or not.