<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /path_to/xenforo/installation
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^(data|js|styles|install) - [NC,L]
RewriteRule ^.*$ index.php [NC,L]
</IfModule>
[/php