In message , at 11:24:32 on Tue,
22 Jan 2013, Theo Markettos
remarked:
Oyster supporting a maximum of 15 fare zones looks like a bit short-sighted.
I think we're up to 12 already (according to another thread here or in
uk.r).

Something to add to the list of:

"There will never be more than 256 networks on the Internet"

etc.
--
Roland Perry