POSTNET: A Predecessor to IMb Used for Encoding ZIP Codes

An in-depth look at POSTNET, its historical context, significance in postal services, detailed explanations, comparisons, and more.

POSTNET (Postal Numeric Encoding Technique) was a barcode symbology used by the United States Postal Service (USPS) to assist in directing mail. POSTNET encodes ZIP codes, which facilitate automated sorting and delivery. Although it has largely been replaced by the Intelligent Mail barcode (IMb), POSTNET played a crucial role in the evolution of postal automation.

Historical Context

Origins and Development

• 1982: POSTNET was introduced by the USPS as part of an effort to streamline and automate mail sorting processes.
• 1980s and 1990s: POSTNET became widely used, significantly enhancing the efficiency and speed of mail delivery.
• 2006: USPS announced the Intelligent Mail barcode, aiming to provide more data and greater functionality, eventually phasing out POSTNET.

Transition to IMb

The transition from POSTNET to IMb began in earnest in the late 2000s, driven by the need for more advanced tracking and additional information encoding capabilities. IMb combines the data encoded in POSTNET and PLANET barcodes into a single, more versatile barcode.

Types/Categories

Basic POSTNET Barcodes

• 5-Digit ZIP Code: Encodes the standard ZIP Code.
• ZIP+4 Code: Encodes the extended ZIP+4 code for more precise geographic areas.
• Delivery Point Code: Encodes the full delivery point code, combining the ZIP+4 code with a 2-digit delivery point code.

Structure of a POSTNET Barcode

• Frame Bars: Guard bars at the beginning and end of the barcode.
• Bars: Each digit is represented by a combination of five bars, two of which are tall (half-bars) and three are short (full-bars).

Key Events

Key Milestones

• 1982: Introduction of POSTNET by USPS.
• 2006: Announcement of IMb.
• 2009: Full deployment and adoption of IMb, leading to the gradual phase-out of POSTNET.

Detailed Explanations

Encoding Mechanism

POSTNET barcodes are read vertically, with each digit represented by a unique pattern of tall and short bars. The scanning equipment detects these patterns to decode the corresponding ZIP code information.

Example of a POSTNET Barcode

    graph LR
	  A[Start Frame Bar] -- Short bar --> B(1)
	  B -- Tall bar --> C(0)
	  C -- Tall bar --> D(0)
	  D -- Tall bar --> E(2)
	  E -- Short bar --> F(0)
	  F -- Short bar --> G(2)
	  G -- Tall bar --> H[End Frame Bar]

Importance

POSTNET barcodes revolutionized the sorting and delivery processes within the USPS, enabling faster and more accurate mail handling. This advancement allowed USPS to manage larger volumes of mail more efficiently, reducing operational costs and improving service reliability.

Applicability

Postal Services

• Sorting: Automates the process of sorting mail by ZIP codes.
• Delivery: Enhances the accuracy of delivery routing and tracking.

Other Applications

While primarily used by USPS, the principles of POSTNET barcoding have influenced other areas requiring efficient data encoding and automated processes.

Examples

Using POSTNET on a Mail Piece

• Step 1: Encode the ZIP code in the POSTNET format.
• Step 2: Print the barcode on the mail piece.
• Step 3: Use barcode scanning equipment to route and sort the mail.

Considerations

Accuracy

Accurate printing and scanning are crucial for POSTNET’s effectiveness.

Compatibility

Transitioning from POSTNET to IMb requires updated scanning and printing technologies.

Related Terms

• Intelligent Mail Barcode (IMb): The successor to POSTNET, providing additional data encoding capabilities.
• ZIP Code: A system of postal codes used by USPS.

Comparisons

POSTNET vs. IMb

Feature	POSTNET	IMb
Data Capacity	Limited	High
Structure	Simple	Complex
Versatility	Less Versatile	More Versatile

Interesting Facts

• POSTNET’s simple yet effective design helped USPS sort billions of pieces of mail during its time in service.
• Each bar in a POSTNET barcode corresponds to either half a bar or a full bar, making it easy to read and decode.

Inspirational Stories

Revolutionizing Mail Delivery

The implementation of POSTNET marked a significant milestone in postal history, dramatically improving the efficiency and reliability of mail delivery services across the United States.

Famous Quotes

“Automation is driving the transformation of our postal services, making them faster, more reliable, and capable of handling greater volumes.” — USPS spokesperson

Proverbs and Clichés

• “Speed and precision—hallmarks of modern postal systems.”

Expressions

• “Barcode it, sort it, deliver it!”

Jargon and Slang

• Frame Bars: Guard bars at the start and end of a POSTNET barcode.
• Half-bars: Tall bars in a POSTNET barcode.
• Full-bars: Short bars in a POSTNET barcode.

FAQs

What is POSTNET?

POSTNET is a barcode symbology used by the USPS to encode ZIP codes, facilitating automated sorting and delivery.

Why was POSTNET replaced by IMb?

POSTNET was replaced by IMb to provide greater data encoding capabilities and more comprehensive tracking information.

How does POSTNET work?

POSTNET encodes ZIP code digits into a series of bars (half-bars and full-bars) which are scanned to sort and route mail.

References

• United States Postal Service: A History of Postal Automation, USPS Publication.
• Wikipedia: POSTNET
• National Postal Museum: Automating the Mails.

Summary

POSTNET was a pioneering barcode technology that transformed USPS operations by automating the sorting and delivery of mail based on encoded ZIP codes. While it has been succeeded by the more advanced Intelligent Mail barcode, POSTNET’s legacy in postal automation remains significant, showcasing the profound impact of technology on improving efficiency in essential services.