In message , at 01:02:38 on
Sat, 19 Jan 2013, Matthew Dickinson
remarked:
According to the Oyster menu on Southern TVMs,

the unadvertised zone for Broxbourne and Brentwood is zone 11,
and the unadvertised zone for Shenfield is zone 12.

A Zone 1 - 12 travelcard would seem to include Watford Junction (which
is the unadvertised Zone 10), but probably not the lines to Grays.

Is a Brentwood Travelcard actually valid for everywhere Z1-11, or is it
just valid in z1-6, plus the trip from BZ6 to Brentwood?

Which would make it rather like an out-boundary travelcard, I agree.
--
Roland Perry