Hi,
Fred Cisin said:
   Allegedly, map
printers (cartographers) have errors in their
 street maps to help identify blatant copies.  I guess they figure
 the effort to verify all of the street names, etc. makes it
 unlikely that a counterfeiter would catch the deliberate error...
 not sure how this has changed with more modern technology. 
 Monmonier says that it continues.
  
 
The British Ordnance survey and "A to Z" street maps certainly do this.
I found one of their deliberate errors in the latest edition of our
local area map.
--
Cheers,
Stan Barr  stanb at 
dial.pipex.com
The future was never like this!