UPU 4-State barcodes are used for adding identifier tags to UPU postal items. They can be either 57 or 75 bars in length.

Examples

 

 

Data Encoded

The UPU 4-state barcode encodes the following data for S18C and S18D barcodes:

• For S18C Barcodes
  

  Data Element	Length
  UPU Identifier	1
  Format Identifier = 18C	3
  Issuer Code	3
  Equipment Identifier	3
  Item Priority	1
  Serial Number- Month	2
  Serial Number – Day	2
  Serial Number – Hour	2
  Serial Number – 10 Min	1
  Serial Number – Item Number Part	5
  Tracking Indicator	1

• For S18D Barcodes
  

  Data Element	Length
  UPU Identifier	1
  Format Identifier  = 18D	3
  Issuer Code	3
  Equipment Identifier	3
  Item Priority	1
  Serial Number – Item Number Part	12
  Tracking Indicator	1

This barcode type uses a Reed-Solomon error detection and correction scheme.