Через .htaccess
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^forum/theme([0-9]+).html$ /forum/index.php?id=$1 [L]Вот маленький пример
Через .htaccess
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^forum/theme([0-9]+).html$ /forum/index.php?id=$1 [L]