Domain name status: Has the carrier set a customer Prohibition Against deletion protection? Expired domain names cannot be registered. Why?

Sometimes, we open a website. Sometimes we cannot open it. At this time, we query in the webmaster tool, there will be a domain name status: the operator sets the customer to prohibit the deletion of protection information.
This status is good for the customer to avoid accidentally deleting the domain name.
After the domain name expires, it can be registered after the following stages:
1. "renewal grace period": generally 30 days, during which the renewal period can be normal. If the domain name has not been renewed after this time, the domain name will enter the next stage;
2. "Salvation period": the domain name status will be displayed as redemption period. If you want to return the domain name during this period, you need to pay the Registrar a redemption fee of up to several hundred or thousands of yuan, this period is also 30 days. If the domain name is not redeemed during this period, it will enter the next stage;
3. "To be deleted": the domain name status will be displayed as pending delete for a period of 5 days. The domain name will be deleted after 5 days, then you can register.