If the domain name is an ISP 510, then it is also a Root URL if no directory path exists 512. If a directory path exists 514, then the path is compared to a list of known ISP Client Directory paths. No match 516 indicates a Leaf URL, otherwise the directory path level is analyzed 518 for final Root URL determination. If the path is one directory level below the Client Directory path then it is a Root URL 522, otherwise it is a Leaf URL 520.