Roland Perry writes:

In message , at 22:59:46
on Fri, 24 Feb 2012, Charles Ellson
remarked:
What credit card transaction requires a PIN? Those are strictly for
debit card transactions.

All UK transactions.

... other than on-line (or contactless?).

And several other classes of payment[1] transaction including many car
park pay machines and apparently the M6 Toll.

The M6 Toll is at most just over a fiver, which bring it well under the
limit for non-pin contactless. On a french autoroute, however, you can spend a
significant amount without needing a PIN.