| Subject | English | Japanese |
| gen. | n adj-no B class | Ｂ級 |
| radio | class B of an amplifying stage | B級 増幅段 |
| comp., MS | Class B IP address | クラス B IP アドレス (A unicast IP address that ranges from 128.0.0.1 through 191.255.255.254. The first two octets indicate the network, and the last two octets indicate the host on the network. Class-based IP addressing has been superceded by Classless Interdomain Routing (CIDR)) |
| comp. | n class B IP address | クラスＢＩＰアドレス |
| vac.tub. | class B operation | B級動作 |
| construct. | class B river | 二級河川 (にきゅう・かせん) |
| gen. | Class B river system | 二級水系 |
| gen. | Class B rivers | 二級河川 (にきゅう・かせん) |
| gen. | n adj-no class-B | Ｂ級 |
| gen. | n class-B and class-C war criminals | ＢＣ級戦犯 |