1971: There is another kind called 'brown bombers'. They are very interested in parked cars. They put chalk marks on tyres and leave little notes, in envelopes, under windscreen wipers — John O'Grady, Dealing with Cops, from Aussie Etiket, 1971. Quoted in Aussie Humour, Macmillan, 1988, ISBN 0-7251-0553-4, page 200.