In message

, at 08:03:47 on Sat, 9 Aug 2014, Recliner
remarked:

And for places like Dartford the choice would be extending Z6 there,
making it Z7, or creating a brand new 'pseudo-zone'.

Isn't it that already, given that the normally z1-6 limited Freedom passes
are valid there, but zone-6 travelcards aren't.

No, because Oyster PAYG has to know what to charge (based on where you
started, having finished there), something that a Freedom Pass by
definition doesn't.
--
Roland Perry