On Fri, 27 Apr 2007 21:46 +0100 (BST), Colin Rosenstiel wrote:

people who need an extension on a paper travelcard.

AIUI, period Travelcards from out-boundary on National Rail are
valid from z1-6, so the question doesn't arise.

Not so. They can be valid to any of the following:

Z1-6
Z2-6
Z3-6
Z4-6
Z5-6
Z6

Eh? To a London Terminal?

I'm not sure what you mean, but I'll attempt to illustrate my previous
post with an example.

The following season tickets which include Travelcards are available
from Redhill (which is outside Z6):

Redhill to Z1-6
Redhill to Z2-6
Redhill to Z3-6
Redhill to Z4-6
Redhill to Z5-6
Redhill to Z6