this is curious: "The specific ENUM standard, known as E.164.arpa, translates telephone numbers into Internet addresses and vice versa. For example, the telephone number 1-202-555-1234 would be expressed as an Internet address as 4.3.2.1.5.5.5.2.0.2.1.e164.arpa. Users would be spared typing all this out as Web browsers or advanced phones would likely automate the process."