Thanks for the response! Is my understanding correct, that what I can do is recreate the parts of _main.php in a new 'main.inc' file, or divide the code in main.php into 'header.inc' and 'footer.inc' and then include those in my new template file, with my own html sandwiched in there?
Or, a different strategy, don't meddle with main.php and create 'mypartial.inc' and then in my template file:
<?php include("./mypartial.inc");
But if I do this second strategy, how do I ensure my code shows up in the region of the page that i want it (between nav and footer)?