Add comment about os.path.walk()'s behavior with symbolic links.
diff --git a/Doc/lib/libposixpath.tex b/Doc/lib/libposixpath.tex
index 4bbb5b6..d195447 100644
--- a/Doc/lib/libposixpath.tex
+++ b/Doc/lib/libposixpath.tex
@@ -214,4 +214,9 @@
avoid visiting certain parts of the tree. (The object referred to by
\var{names} must be modified in place, using \keyword{del} or slice
assignment.)
+
+Note that symbolic links to directories are not treated as subdirectories,
+and that \var{walk} therefore will not visit them. To visit linked
+directories you must identify them with \var{os.path.islink(file)} and
+\var{os.path.isdir(file)}, and invoke \function{walk()} as necessary.
\end{funcdesc}