In message
,
Andy writes

Those at Kensington Olympia are not within a gated area and, along
with the one at West Brompton, are accessible via trains from outside
the zones without changing (from Milton Keynes). A similar situation,
regarding trains from outside the zones, occurs at Richmond, Wimbledon
and Stratford. My personal feeling is that the information given on
the link is incorrect, unless extra yellow validators have magically
appeared alongside the pink ones (which used to be yellow of course).

It's ages since I last used Olympia, but the pink validators at Richmond
and Wimbledon are within the gated area.

I take your point that someone arriving by NR might attempt to enter the
Oyster system at one of these interchange stations by touching in on a
pink validator. However, while the information on the cited webpage
might be incorrect, it is supported by information that TfL give in
their ticketing and travel guide about pink validators, which indicates
that you'd be liable for a maximum fare if you attempted to start or end
a journey by touching on a pink validator:

"You must still touch in on a yellow card reader (see clause 6.8.) at
the start of your journey and touch out at the end to ensure you pay the
correct Oyster single fare and avoid paying a maximum Oyster fare."
--
Paul Terry