Postal barcodes

Barcode symbologies used in post office. More country have own specifications.

• Some symbologies can be derived from Code39 or Code93 (Danish, French, Dutch postal symbologies)
• use own encoding system ( Telepen, CPC )
• Some use 4-state symbology ( BPO4State, Royal Mail, Singapoore postal, Australia post, Japan Post, Korean, Deutsche 4 state, IntelligentMail...), information isn't encoded into sequence lines and bars with different width, but encoded using lines in four different height ( if we separate bar in height to three same parts ):
  
  

  Basic elements of Postal barcodes:

  
  
  • T - Tracker
  • D - Tracker, Descender
  • A - Tracker, Ascender
  • H - Tracker, Ascender, Descender
• ... or use 2-state encoding - lines are full in height or bottom half ( PostNet ) .