User-agent: *
Disallow: /bitrix/
Disallow: /admin/
Disallow: /banners/
Disallow: /backup/
Disallow: /captcha/
Disallow: /search/
Disallow: /forum/

User-agent: MJ12bot # http://www.majestic12.co.uk/projects/dsearch/mj12bot.php
Disallow: /