Can someone please explain why all the Oyster fares to the four c2c stations
which are outside the Travelcard zones but inside the Oyster PAYG area
include validity within zones 7, 8 and 9? These three zones have absolutely
nothing to do with c2c, and the number of people who need validity e.g. to
Grays *and* to Zone 9 must be vanishingly small. The area containing these
four stations is contiguous with Zone 6, so why not (for example) "Zone 1-6
+ Grays"?