21 Sep 15 09:45, you wrote to me:   
      
    HG>> Have you confirmed that PKUNZIP or Infozips UNZIP cannot handle 7-ZIP   
    HG>> compressed files?   
      
    ml>> 7-zip defaults to its 7z format... pkunzip can't recognize it   
    ml>> because the signature "7Z" is different than "PK"...   
      
    HG> Thanks for the info. Of course I have noticed the first two characters   
    HG> of ZIP-files but I can't recall having seen PK up there in the top left   
    HG> corner. "MZ" plus an additional character seem to be common in both   
    HG> normal and PKLited files.   
      
   yes, MZ indicates one of the binary executable formats... there are several...   
   PE is another one, IIRC... i think it indicates a type of windows   
   executable... here's a link to a page with a lot of file signatures and their   
   offsets...   
      
     https://en.wikipedia.org/wiki/List_of_file_signatures   
      
   )\/(ark   
      
   ... Obscenity is whatever gives the judge an erection.   
   ---   
    * Origin:  (1:3634/12.73)