diff --git a/documentation/optimization.html b/documentation/optimization.html
index 7f8f23cd7d..3a13c3de9c 100755
--- a/documentation/optimization.html
+++ b/documentation/optimization.html
@@ -453,15 +453,15 @@ For that is required to load header module
 in apache (check with a2enmod in your favorite root terminal)<br />
 add theses line after RewriteBase /courses/:
 <pre>
-<IfModule mod_headers.c>
+&lt;IfModule mod_headers.c&gt;
     # all file name ended with these  extensions names will bypass the permission check   (and also served by the browser cache at  the next request)
-    <FilesMatch "\.(gif|jpg|jpeg|png|js|pdf|ico|icon|css|swf|avi|mp3|ogg|wav|ttf|otf|eot|woff)$">
+    &lt;FilesMatch &quot;\.(gif|jpg|jpeg|png|js|pdf|ico|icon|css|swf|avi|mp3|ogg|wav|ttf|otf|eot|woff)$&quot;&gt;
         Header unset Cache-Control  
-        Header set Cache-Control "public, max-age=29030400" 
+        Header set Cache-Control &quot;public, max-age=29030400&quot; 
         RequestHeader unset Cookie      
         Header unset ETag
-    </FilesMatch>
-</IfModule>
+    &lt;/FilesMatch&gt;
+&lt;/IfModule&gt;
 </pre>
 <hr />
 <h2><a name="12.MySQL-compression"></a>MySQL/MariaDB compression</h2>