The inability to read more than six words at a given moment. With the onslaught of mass advertising especially on billboards, humans have become accustomed to reading words at speeds of 25mph to 65mph (legally). Advertisers must keep the number of words down to around six as to make the ads stand out with large fonts.
Billboard Syndrome presents itself when some one is given a document to read with more than twenty words, and they only read several (average of six) of those words. It is primarily used by Technical Support and System Admins, when giving written instructions (such as to access an e-mail address account or other company or organization system), and still call the Help Desk or Sys Admin for help.