The server side includes panel is part of the Configure Dialogue.
This module consolidates Server Side Includes, optionally generating a corresponding version of the site. Here is an example of a Server Side Include:
<!--#include virtual=‘x.inc’>
SSC does not process complex conditions in <!--#if ...> expressions.
Server Side Includes offer a number of variables. Here, you can preset default values for some of those variables.
The <!--#exec ...> server side include is potentially unsafe when analysing websites which you do not trust. Here, you can specify a message that should be output when an <!--#exec ...> is encountered, instead of running the command.
You may specify a specific last modification instead of that of the page being processed, and a specific time to use instead of the current time. This is particularly useful when you are processing a copy of a website, rather than its original root.