ImageGear .NET v25.0 - Updated
Royal Post 4-State Barcode
User Guide > How to Work with... > Barcodes > Supported Barcode Types > Royal Post 4-State Barcode

The United Kingdom has implemented a new 4-state barcode referred to as the Royal Mail 4-State Customer Code (RM4SCC).
 
An example:

This barcode type is used by the Royal Post. It encodes 5, 6, or 7 character post codes along with a two character Delivery Point Suffix (DPS). A checksum character is included to verify the barcode read.