In message 0, David
Jackman writes
How is this supposed to work? How will the validators at Stratford tell
between a Highbury and Islington to Stratford via OXO onward via National
Rail and a Highbury and Islington to (say) Leyton via NLL? Or does the
user need to validate both "in" (through the barrier) then "out" (on the
platform, I assume one has been provided) at Highbury, "in" at Stratford
and then "out" at Mile End? What a performance!

(1)
This is how I think it may be working.
Start journey on Victoria Line at Highbury and Islington (1st touch
reader at entry)
Change to Central Line at Oxford Circus (no reader)
Leave at Stratford (2nd touch of reader at exit)

(2)
Start journey at Highbury and Islington (1st touch at entry)
leave NR at Stratford ( use 2nd reader at continuation exit or possibly
Jubilee Line UTS gates)
Join Central Line.
Leave at Leyton (3rd touch of reader at exit)

I don't know Stratford (except the upper level Central/DLR/NR) part well
enough to know if you have to go through the Jubilee line gates to leave
the lower NR part of the station or if there are validators on the lower
NR platforms. Also, I don't know Highbury and Islington at all.
Maybe someone who uses these stations can tell me.
--
Kat Me, Ambivalent? Well, yes and no.