diff --git a/public/develop/deployment_guide/configure_your_machine/physical_server/index.html b/public/develop/deployment_guide/configure_your_machine/physical_server/index.html
index 643aacb58397c06347979baa3b277fb09c7c177f..ee0b79b99b7d9501fff76ce292d69af0d862a57a 100644
--- a/public/develop/deployment_guide/configure_your_machine/physical_server/index.html
+++ b/public/develop/deployment_guide/configure_your_machine/physical_server/index.html
@@ -762,21 +762,21 @@
 
 <p>This page describes how to configure a physical server for running ETSI TeraFlowSDN(TFS) controller.</p>
 <h1 id="server-specifications">Server Specifications</h1>
-<h3 id="minimum-server-specifications-for-development-and-basic-deployment">Minimum Server Specifications for development and basic deployment</h3>
+<h4 id="minimum-server-specifications-for-development-and-basic-deployment">Minimum Server Specifications for development and basic deployment</h4>
 <ul>
 <li>CPU: 4 cores</li>
 <li>RAM: 8 GB</li>
 <li>Disk: 60 GB</li>
 <li>1 GbE NIC</li>
 </ul>
-<h3 id="recommended-server-specifications-for-development-and-basic-deployment">Recommended Server Specifications for development and basic deployment</h3>
+<h4 id="recommended-server-specifications-for-development-and-basic-deployment">Recommended Server Specifications for development and basic deployment</h4>
 <ul>
 <li>CPU: 6 cores</li>
 <li>RAM: 12 GB</li>
 <li>Disk: 80 GB</li>
 <li>1 GbE NIC</li>
 </ul>
-<h3 id="server-specifications-for-best-development-and-deployment-experience">Server Specifications for best development and deployment experience</h3>
+<h4 id="server-specifications-for-best-development-and-deployment-experience">Server Specifications for best development and deployment experience</h4>
 <ul>
 <li>CPU: 8 cores</li>
 <li>RAM: 32 GB</li>