At the end of each document, I'd like to include my signature but don't want to have to change every document I wrote when my home document moves. So, I can use a server include tag to include it, like this:
Note:
Having the server parse documents is a double edged sword. It can be costly 
for heavily loaded servers to perform parsing of files while sending them. 
Further, it can be considered a security risk to have average users executing
commands as the server's User. 
If you disable the exec option, this danger is mitigated, but the performance 
issue remains. You should consider these items carefully before activating 
server-side includes on your server. 
NCSA httpd Development Team
httpd@ncsa.uiuc.edu