diff --git a/functions/filesystem.xml b/functions/filesystem.xml
index 98b6557620..0e9bb576f1 100644
--- a/functions/filesystem.xml
+++ b/functions/filesystem.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.95 $ -->
+<!-- $Revision: 1.96 $ -->
  <reference id="ref.filesystem">
   <title>Filesystem functions</title>
   <titleabbrev>Filesystem</titleabbrev>
@@ -2185,11 +2185,6 @@ mkdir ("/path/to/my/dir", 0700);
      </funcprototype>
     </funcsynopsis>
 
-    <para>
-     This function is available only in versions of PHP 3 after PHP
-     3.0.16, and in versions of PHP 4 after 4.0.2.
-    </para>
-
     <para>
      This function checks to ensure that the file designated by
      <parameter>filename</parameter> is a valid upload file (meaning
@@ -2221,6 +2216,12 @@ mkdir ("/path/to/my/dir", 0700);
 
     &note.sm.uidcheck;
 
+    <warning>
+     <para>
+      If the destination file already exists, it will be overwritten.
+     </para>
+    </warning>
+
     <para>
      See also <function>is_uploaded_file</function>, and the section
      <link linkend="features.file-upload">Handling file uploads</link>