JIS semiconductor designation
has standard JIS-C-7012 for semiconductor part numbers. The first digit denotes the p-n junction count ; then follows the letter "S", then:
| 2nd letter | Type of semiconductor |
| Diode |
| A | high frequency PNP BJTs |
| B | audio frequency PNP BJTs |
| C | high frequency NPN BJTs |
| D | audio frequency NPN BJTs |
| E | Diode |
| F | Thyristor |
| G | Gunn diode |
| H | UJT |
| J | P-channel FETs |
| K | N-channel FETs |
| M | TRIAC |
| Q | LED |
| R | Rectifier |
| S | Signal diode |
| T | Avalanche diode |
| V | Varicap |
| Z | Zener Diode |
Then follows the Japan Electronics and Information Technology Industries Association's Electronic DEvice REgistration Center -assigned part number, optionally followed by suffixes to denote variants, such as tighter hFE groupings.
Example: 2SD965, but sometimes the "2S" prefix is not marked on the package – a 2SD965 might only be marked "D965"; a 2SC1815 might be listed by a supplier as simply "C1815", thus possibly creating confusion with Pro Electron abbreviated markings, because a transistor marked "D965" might either be a 2SD965 or a BD965.
