DAFT Generator

What Is DAFT?

DAFT isn't a postal authority's barcode standard the way RM4SCC or Australia Post's 4-State code are — it's a descriptive notation used to talk about and construct any 4-state postal barcode directly. The letters stand for the four vertical bar positions every 4-state postal symbology is built from: Descender (bottom half only), Ascender (top half only), Full (the complete bar, top to bottom), and Tracker (a short segment in the middle only).

A daft generator lets you type a string made up of those four letters and render the exact bar pattern that results, bar by bar, without needing the character-encoding tables that translate postcodes or customer data into DAFT sequences for a specific national postal format. It's the lowest-level way to see and control a 4-state barcode's appearance.

How DAFT Notation Works

Every real-world 4-state postal barcode — Royal Mail's RM4SCC, Royal Mail Mailmark 4-State, Australia Post's 4-State Customer Barcode, and Japan Post's barcode — ultimately reduces to a sequence of bars in one of these four states. Postal standards define lookup tables that convert each valid input character (a digit, a letter, a checksum value) into a fixed pair or group of DAFT letters. A DAFT generator skips that translation layer and lets you specify the bar states directly, one letter per bar position.

This makes DAFT notation useful as a building block: developers implementing a new 4-state barcode encoder, or engineers verifying that a particular bar sequence prints and scans correctly, can type the exact D/A/F/T string they want to test rather than reverse-engineering it from postcode data.

Technical Specifications

A DAFT-notation barcode accepts a string composed only of the characters D, A, F, and T (case-insensitive in most implementations), with each character corresponding to one printed bar in the resulting 4-state symbol. There's no checksum, start/stop pattern, or character-set validation applied at this level — DAFT is a direct bar-state description, not a data-carrying symbology with its own encoding rules. Bar height follows the same convention used across 4-state postal codes: a Full bar spans the entire vertical height, an Ascender occupies the top half, a Descender occupies the bottom half, and a Tracker is a short middle segment, all evenly spaced along the horizontal axis.

Because it has no built-in error detection, DAFT output is best treated as a visual and structural reference rather than a barcode meant for live postal sortation.

Where DAFT Is Used

DAFT notation shows up primarily in technical and development contexts rather than on finished mail pieces:

• Barcode library and encoder development — engineers building or testing 4-state barcode rendering libraries use DAFT strings to verify bar-drawing logic independent of postal encoding tables.
• Postal specification documentation — technical specs for RM4SCC, Mailmark, Australia Post, and Japan Post barcodes often describe example bar patterns using D/A/F/T notation.
• Print and scanner calibration — print shops and equipment vendors use known DAFT sequences to test that a printer or scanner correctly reproduces and reads all four bar states.
• Educational and reference material — DAFT is a common way to explain 4-state postal barcodes conceptually without requiring readers to know a specific country's data-encoding rules.

How to Create a DAFT Barcode in Barcode Mint

Select DAFT from the Postal Code group in the symbology list. Type a string of D, A, F, and T characters directly — each letter renders as one bar in the live preview, updating instantly as you type so you can see exactly how a given sequence looks before exporting. From there:

• Adjust bar height and spacing to test how a sequence would appear at different print scales.
• Use solid black on a light background to match how postal scanners actually read 4-state bars, even though DAFT output itself isn't tied to a live postal service.
• Export as PNG or SVG for use in documentation, encoder test suites, or print calibration sheets, or use Copy to paste the image into other tools.
• Use the bulk CSV → ZIP/PDF tool if you need to generate and export multiple DAFT test patterns in one batch.
• Call the REST API — /barcode?type=daft&data=YOURDAFTSTRING — to generate DAFT bar patterns programmatically from a test harness or documentation pipeline.

Printing and Scanning Best Practices

Since DAFT output mirrors the visual structure of real 4-state postal barcodes, the same print discipline applies when using it for calibration or testing:

• Print in solid black ink on a light, matte surface, matching the contrast conditions real postal optical sensors expect.
• Preserve accurate bar height ratios between Full, Ascender, Descender, and Tracker states — if your printer or scanner can't distinguish these cleanly on a DAFT test pattern, it likely can't reliably read a production RM4SCC, Mailmark, Australia Post, or Japan Post barcode either.
• Keep a clear quiet zone around the pattern, since 4-state bars are closely spaced and sensitive to interference from nearby print.
• Use a DAFT test string covering all four bar states in combination when calibrating new print or scan hardware, rather than testing with a single repeated state.
• Remember that DAFT patterns have no checksum — visually verify output carefully, since there's no built-in error detection to catch a misprint.

DAFT vs Related Postal Codes

DAFT is not a competing standard to RM4SCC, Mailmark 4-State, Australia Post's 4-State Customer Barcode, or Japan Post's barcode — it's the shared notation underlying all of them. Where those symbologies define specific character sets, checksums, and start/stop markers on top of the four-state bar mechanic, DAFT strips that away and lets you specify bar states directly. Use a DAFT generator when you need to test, document, or visualize raw 4-state bar patterns; use the country-specific postal symbologies when you need a barcode that an actual postal service's sorting equipment will accept and route mail with.

Common uses

• 4-state barcode encoder and rendering library development
• Postal specification documentation and technical examples
• Print and scanner calibration for 4-state bar detection
• Educational material explaining 4-state postal barcodes
• Manual construction of custom 4-state test patterns

Frequently asked questions

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