This was an epic pain to figure out as no one seems to have a list of common variables for the CMS in vb4. Oh, the regret of using this CMS.
Anyway, if you need the variables for parentnode and node to do section dependent stuff in your templates, here they are:
PHP Code:
{vb:raw $vbulletin->nodeid}
{vb:raw $vbulletin->parentnode}
It's not much, but maybe it'll save you guys the hours and hours it took me to figure out.