From: benlizro@ihug.co.nz   
      
   10-4: Acknowledged; can also be used to denote or emphasize an agreement   
   ("That's a big 10-4.").   
      
   "The day was launched by the US telecommunications company Motorola in   
   1977, when CB radio use was common among police forces, truckers, and   
   amateur radio enthusiasts.   
   The technology has now been largely replaced by cell phones and other   
   digital devices."   
      
   Ah well then...   
      
   History, technical stuff, and a list of "10-codes" here:   
      
   https://en.wikipedia.org/wiki/Citizens_band_radio   
   https://en.wikipedia.org/wiki/List_of_CB_slang   
      
   [A series of numerical codes for common messages was set up, but when   
   one of these occurred at the beginning of transmission, the equipment of   
   the day often cut off the first syllable. "10-" was added as expendable   
   filler.]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)