Options +FollowSymlinks
RewriteEngine on
RewriteRule ^([a-z0-9_\-]*-(f|all)[0-9]+(p[0-9]+|/forumdisplay[0-9]*)?\.php)$ index.html/$1 [QSA,L]
RewriteRule ^([a-z0-9_\-]*-(t|p)[0-9]+(p[0-9]+|/showthread[0-9]*)?\.php)$ index.html/$1 [QSA,L]
RewriteCond %{REQUEST_URI} !(index\.php|\.css) [NC]
RewriteRule ^(archive|sitemap)/(.*)$ $1/index.php/$2 [QSA,L]