Domain name warehousing
Domain name warehousing is the practice of registrars obtaining control of expired domain names already under their management, with the intent to hold or “warehouse” names for their own use and/or profit.
Typically this practice occurs after a domain name has expired and the previous (registrant) has not exercised his or her right to renew the name within the allotted time frame; usually 45 days following expiration. A domain's expiration date and time can be calculated based on the expiration date in the WHOIS and the redemption grace period of the registrar managing the domain registration.