On Sat, 7 Feb 2004, David Biddulph wrote:

"Phil" wrote in message
To answer the original question the person who wishes to travel 10
times from boundary six to Watford and backon the same day would buy
the travel card
and not spend £30 on CDRs

I thought that a one day travelcard only allowed one return journey from the
station outside the zones,

Correct. On arrival back at the starting point, the whole ticket's
validity technically ceases (even if one somehow went to London again
later the same day).

and that it was only within the London zones that
one was allowed unlimited travel?

But not after having used the return portion.

Of course, whether this can be enforced in practice is a different
question. But if there's an automatic barrier, then it's reported
that it swallows the ticket after the return leg, which came as a
surprise to some.