Singapore 4 State Postal Barcode is a type of linear barcode with varying length of vertical bars, used to encode alphanumeric data in Singapore Postal Services commonly known as SingPost. This barcode symbology is based on 4 state barcode standard where each character is represented by four vertical bars having variable length. Singapore 4 State Postal barcode is capable of encoding numbers from 0-9 and the alphabets from A-Z. It cannot encode special characters.
History
British Post, the Royal mail developed 4 state barcode standard known as Royal Mail barcode in three years. Royal Mail Barcode was developed between 1992-1994. Based on the same 4 state barcode standard, Singapore post developed its own barcode standard in the year 1997. This barcode standard was almost similar to the Royal Mail Barcode with a difference in algorithm used to calculate checksum digit. This 4 state barcode standard was further followed by the Australian Post and the Canadian Post Corporation and they developed their own 4 state barcode standards in 1998. All of these 4 state barcodes standard are same. As mentioned earlier, the difference is only in the checksum digit calculation algorithm.
Advantages
Advantages and limitations of Singapore 4 State Postal Barcodes are more or less same as the other 4 state barcodes such as Royal Mail Code. The advantages are as follow:
· The algorithm used to encode and decode information from the 4 state barcode is extremely simple and easy to understand hence time is not wasted on user trainings of such barcodes.
· Alphanumeric barcodes can be read very quickly, therefore 4 state barcodes are fast to read.
· Hardware devices and scanners, needed to decode information from these barcodes are very simple and cheap.
· Checksum digit automatically ensures that the security of the barcode is retained in case of 4 state barcode.
Limitations
· Low data density barcode, not capable of storing much information in small area.
· Once 4 state barcodes have been damaged or distorted they cannot be recovered and information cannot be decoded due to poor fault tolerance.
· Singapore 4 State Postal Barcode is not capable of encoding special characters and all the 128 ASCII characters cannot be encoded with this standard.
Usage
Singapore Postal Services namely SingPost is the largest user of this barcode standard, in fact it is designed keeping in view the requirements of the Singapore postal industry. With this barcode, routing information of the mail such as delivery points, destination and receiver’s information is encoded in Singapore Postal services.