In message , at
16:43:00 on Sun, 2 Oct 2011, Paul Cummins
remarked:
Today's routing guide says the only map to use for such a ticket is
EE (initially I suppose it may have said WA[1]), which reveals just
two mapped routes (which are also direct trains, so the map isn't
adding anything) to Kings Cross and Moorgate.

So how does one get to Liverpool Street?

On a Finsbury Park to London Terminals ticket? Not at all, I presume.
(Other than "Moorgate and walk a hundred yards")

See the quite good wording signposted earlier:

"Tickets issued for travel to/from London usually show 'London
Terminals' as the destination/origin rather than naming a
specific station. This is because the ticket is valid to more
than one London Terminal station provided it’s on any
reasonable line of route. Tickets can only be used on National
Rail services. For example, a ticket from Brighton to London
Terminals is valid to Victoria, Waterloo (changing at Clapham
Junction), London Bridge, Blackfriars and City Thameslink or
Charing Cross Waterloo East or Cannon Street (changing at London
Bridge). It would not be valid to, for example, London Euston or
Paddington as this would not be on the line of route and would
involve crossing London using another mode of transport."

--
Roland Perry