1. A method, comprising: receiving, by a computer, a request to register an expression defining a set of second level root domain names in a domain name system for a wide area network, wherein the expression is defined by one or more ASCII characters and one or more wildcard or other pattern-matching symbology, and wherein the set of second level root domain names includes more than one unique second level root domain member; determining, by the computer, registrability of the set of second level root domain names based on the expression including the one or more wildcard or other pattern-matching symbology; reporting results of evaluating the request to a client, wherein the report includes information identifying any member of the set of second level root domain names that is already registered in the domain name system; and preparing an modified expression by adding a term that specifically excludes at least one member of the set of second level root domain names that is already registered in the domain name system, wherein the modified expression includes the one or more wildcard or other pattern-matching symbology.