I was watching Map Man earlier this evening and during the course of a programme on the A-Z it emerged that there are about a hundred deliberate mistakes in that book. In order to protect their copyright, the company renames (or invents, it wasn't entirely clear to me) a number of small streets - paths, walks, i.e. places where nobody lives - so that if anybody else simply reproduces their work, instead of going round mapping the city themselves, the mistakes are reproduced in the pirated copy, exposing the copying. I wonder if this was standard procedure in urban cartography? I also wondered, more directly relevant to the London map itself - does anybody know, have they noticed, any of these phantom roads?