Source : WordNet®

white pages
     n : a telephone directory or section of a directory (suually
         printed on white paper) where the names of people are
         listed alphabetically along with their telephone numbers

Source : Free On-Line Dictionary of Computing

White pages
     
        A directory service for locating individuals by name (by
        analogy with the telephone directory).  The {Internet}
        supports several {database}s that contain basic information
        about users, such as {electronic mail} addresses, telephone
        numbers and postal addresses.  These databases can be searched
        to get information about particular individuals.  See
        {Knowbot}, {Netfind}, {whois}, {X.500}, {finger}.