On 3 Nov 2005 05:39:01 -0800, "Mizter T" wrote:

But would I be able to complete the same journey on a printed ticket? I
reckon I should be able to, but I'd be anxious that the automatic gates
at Euston would retain it, under the logic that my ticket was a Zone
1-4 single and I'd just completed a journey from Zone 4 into Zone 1.

Such anxiety ought to be unnecessary - it's a result of a lack of
information being made available to passengers. This is why I think a
list of permitted out-of-station interchanges should be made
available.