How to close the main domain from indexing, but allow sub domains to be indexed?

Question

Google

Actually there is a main domain on which I work for a very long time and it is closed from the index. But there is a blog on the sub domain, where everything is ready. Yandex does not allow indexing a subdomain in case of blocking the main one + as far as I understand Google Adsence also does not allow advertising on subdomains with a closed main domain. Maybe someone faced with this kind of problem.

Answer 1

A subdomain is a separate site. What does it mean, "Yandex does not allow indexing a subdomain if the main one is blocked"?