where do the __xx__ come from in the file?

I'm editing my templates and I see codes in the form of __XXX__ which I assume gets parse and then gets converted to HTML. For instance, I modifed my header to be very custom by commenting out

<div class="topBlock">
<!--__main_logo__
__hello_member__-->

and replacing inside the <div> block with my own HTML. So, where can I find where __hello_member__ is parse at?

Anyone knows?

design_inc.php function PageCode() deals with the parsing of the templates.  You will find the codes as an example:

$_page_cont[$_ni]['page_main_code'] = PageCompPageMainCode();
replaces __page_main_code__ in the template with the returned function.

They are different in each php file, but the core __xxx__ are in design.inc.php

:)

Chris