Most IPv4 delegations correspond to a single "/prefix" address range.
Some IPv4 delegations correspond to several consecutive "/prefix" ranges with the same holder, aggregated together in a single delegation (for example a /23 and the following /24 aggregated in a delegation with 768 addresses). In this case, colum "Prefix" in the following table contains the keyword "Aggreg", and the entry in the "IPv4 List" text file appears as "First address-Last address".