Ive always used includes of some form or another but dont know which is better in the seo guise. Personally I cant see why either would be classed bad or wrong but cant harm having other opinions.
Both do the same thing but which should be used and more importantly WHY?
Code:
standard html written in php files to allow <?php include("aaa.php"); ?>
or standard shtml files with <!--#include file="aaa.html"-->
Both do the same thing but which should be used and more importantly WHY?