There are illegibilities of the layered depths in a single place, of ruses in action and of historical accidents.  The writing of these evocations is sketched out, ironically and fleetingly, in graffiti, as if the bicycle painted on a wall, the insignia of a common transit, detached itself and made itself available for indeterminate tours.

Michel de Certeau, The Practice of Everyday Life, Berkeley: University of California Press, 1988, p 200