Japanese postal barcode
The Japanese postal barcode is used in mail sorting for Japan. It encodes an 7-digit postal/zip code plus an optional alphanumeric address code. The symbology allows the coding of the digits 0-9, letters A-Z, and hyphen. An alternative mode allows for encoding SHIFT-JIS (CP936) as alphanumerics.
This sort of bar code system is regarded as "four-state" because there are four types of bars, classified by presence of ascenders and/or descenders. This sort of system is transcribable using DAFT notation. These sorts of bar codes are used by a number of countries in their postal systems, though the specific symbologies by which they encode characters can vary.
Example codes
There are no descriptions of how the barcode works in English. The relevant article on Japanese Wikipedia, Wikipedia:ja:郵便追跡サービス, has no information either.
Each character appears to occupy three bar units. "TDA" stands for a padding control character.
