Styles & Templates > Style Manager >
Next to the style you are editing click <<>> to expand templates
Forum Display Templates > FORUMDISPLAY
Add the code after this
Code:
$stylevar[htmldoctype]
<html dir="$stylevar[textdirection]" lang="$stylevar[languagecode]">
<head>
$headinclude
<title>$foruminfo[title_clean]<if condition="$pagenumber>1"> - <phrase 1="$pagenumber">$vbphrase[page_x]</phrase></if> - $vboptions[bbtitle]</title>
<if condition="$show['inlinemod']"><script type="text/javascript" src="clientscript/vbulletin_inlinemod.js?v=$vboptions[simpleversion]"></script></if>
</head>
<body>
$header
$navbar
ADD CODE HERE