requirement for 802.11b access from Narita Express trains

[itojun]

        For those of you coming to Yokohama -

        As promised, there's 802.11b wireless Internet access (of course
        with IPv6) available from Narita Express train, from Narita airport
        to Yokohama station.

        Note, however, the following items are required to use it:
        - Get a ticket for Green car (first class) instead of economy class.
        - you have to visit http://www.nex.v6pc.jp/en/ for sort-of
          authentiation/authorization.

itojun