On Tue, 7 Sep 2010 10:46:53 -0700 (PDT), Mizter T
wrote:

You've missed the crucial wording "start a journey within the zones
covered by your Travelcard and want to travel outside those zones on
National Rail" - at Richmond, your colleague was *not* starting a
journey within the zones covered by his Travelcard, hence there was no
requirement for him to set an OEP.

Thanks (all who responded. I think I understand, though probably will
never need to know as I'm unlikely to ever get a Travelcard!).

I understand the *literal* meaning of the statement, but given the
obfuscation occasionally employed in rail speak wanted to clarify
whether 'start a journey' really meant one from within a zone to
outside or could also cover the return part - i.e. not treat each as a
single journey (though that does go against the principle of Oyster
PAYG not doing return fares and relying instead on the daily cap).