If you use it you can keep it. If you turn off e.g. your email service after 1 year you lose the domain.
This is actually somewhat easier to check than it might seem, because you can buy a domain on any registrar and it won't have any services associated with it; the hosting or servers pointing to it are completely independent from the domain name which is only rented from ICANN.
Some people take domains like this for email purposes. Allowed or not allowed?
If you use it you can keep it. If you turn off e.g. your email service after 1 year you lose the domain.
This is actually somewhat easier to check than it might seem, because you can buy a domain on any registrar and it won't have any services associated with it; the hosting or servers pointing to it are completely independent from the domain name which is only rented from ICANN.