"Martin Underwood" typed

Forgive an equally naive supplementary: what is "capping" in this context?

Limiting the amount that will be deducted from Oyster PrePay balance for
one day's use.

If the traveller only uses buses, the amount is 'capped' at £3, the cost
of a One Day Bus Pass is normally £3.50.

The amount capped is 50p below the equivalent paper ticket.

If the traveller uses buses and the Tube, the amount capped is also 50p
below the equivalent Travelcard. (eg a Zone 1-4 paper Travelcard is
£5.40, but only £4.90 will be deducted from Oyster PrePay balance for
all travel within these Zones in a day.)

This is fine until the traveller wishes to use National Railways, where
Oyster PrePay is usually not accepted, but paper Travelcard are...

--
Helen D. Vecht:
Edgware.