ok, i think i sort of understand. the tags will only work when a template file is read from a php file e.g.
$site_template->print_template($site_template->parse_template($main_template));
am i understanding this right? that is a shame, i wish it would just parse / read the tags from include files called from templates.
what if i want to call a template within a template?
this is what i am trying to achieve. the templates are labourious to update. if i make a change i generally have to update all of them. since nearly all of the templates are indentical except for the contents of one table cell, i would like the non changing content to be one file and the changing content as another file. this way if i update a header or something like that, then i don't have to edit all of the templates.