With NW-7, it is easy to print serial numbers, for its comparatively simple bar compositions and discrete type, and relaxed gaps, and it is so often used for some management business which serial number printing is needed, such as blood management, slips of home-delivery services, library management, registered mail management, etc.
We can choose start and stop characters from four alphabet: a, b, c, d, so there is 16 patterns (4 x 4) of combination; and that indicates the content of data.
checkdigit is not needed.
If used, 7 (or 9) check is often used for its easiness for
serial number printings.
In Japan, it is standardized as JIS X 0503, in 1994.
| * character set กกกก | 4 types of Start/Stop
character
Numerics, 10 arphabet characters and marks |
| * Code type | discrete |
| * Length of symbol | variable |
| * Self check | yes |
| * Checkdigit | optional |
| * Character Density | about 5 chars/cm |
![[Character composition of NW-7]](../shurui/images/00-99/20.gif)