GreenGeeks does support Server Side Includes.
SSI are commonly used to include the contents of one or more files into a web page. For example, including a common piece of code throughout a site, such as a page header or footer, or navigation.
A simple include looks like: <!‐‐#include file=”header.txt”‐‐>
Pages that make use of includes should be saved and uploaded with the .shtml extension (not .html).
While scripting languages like PHP have eclipsed many of the uses of SSI, they are still a valuable tool in cases where a quick and easy solution is needed. Learn more about Server Side Includes.