On Mon, 29 Jan 2007 11:17:06 GMT, Olof Lagerkvist wrote:

If you touch in at Marylebone en route, is an adjustment made to
reduce the fare into London, i.e. you would still pay £2 or do you end
up paying £3 or £5 in total?

I have not tested that particular route but a couple of months ago I
tested serveral different ways of getting from Tottenham Hale to Canary
Wharf with Oyster PAYG but found none of them charged as via Z1. My
usual route, 'one' to Stratford and then DLR is of course not via Z1.
Then, when tested to touch in to the tube system at T. Hale and used
Victoria Line - Jubilee Line it still was not charged as via Z1 although
there is virtually no way of getting by tube between those without going
through Z1. Next test was to just for fun taking 'one' to Liverpool
Street, Circle Line from there and then DLR from Tower Hill it was still
not charged as via Z1, although I had in this case of course actually
touched several validators within Z1...

Thank you - I think this all but answers the question.