[Zahl]

OK, I tries this, but no luck. It really seems like the headerinclude template gets parsed before any of my code gets executed, so the conditional that checks for my stuff always finds nothing.... Any ideas what I'm doing wrong?

I'll take a look at the threadview stuff now, as it is using conditionals too....

--------------- Added [DATE]1214578283[/DATE] at [TIME]1214578283[/TIME] ---------------

OK, this is my solution now:
I added headinclude to the global templates
I add keywords via
$vbulletin->options['keywords'] .= ', my keyword';
And then I do a
eval('$headinclude = "' . fetch_template('headinclude') . '";');
before I fetch the final page template that uses $headinclude...