For legal reasons I thought I'd better get a recent example... and it wasn't hard to find.
Just near my house over the weekend I noticed the following:

Suspension warning notice ref N22971
Observed Sat 7th June 2008
Top of Mill Lane near where it joins the Finchley Road.
The region to become suspeded reached within eight meters of a completely unmarked post. Given that only one set of wheels needs to be within the zone in order for a car to get a ticket, you could be towed away and get charged £200 when one end of your car was just about six(!) meters from an unmarked post.

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