RewriteEngine on
RewriteRule ^([0-9]+).html file.php?f=$1 [L]
RewriteRule ^category/([0-9]+)/([_A-Za-z0-9-]+)/?$ browse.php?c=$1 [L]
RewriteRule ^category/([0-9]+)/([_A-Za-z0-9-]+)/([0-9]+).html browse.php?c=$1&page=$3 [L]
RewriteRule ^profile/([0-9]+).html profile.php?u=$1 [L]
RewriteRule ^page/([0-9]+).html page.php?p=$1 [L]