noun
first issue; first number
Used for the inaugural issue of a magazine, journal, or serial publication.
この雑誌の初号は1980年に発行された。
The first issue of this magazine was published in 1980.
noun
No. 1 type; first model
Refers to the first version or model of something, often in technical or product contexts.
この機械の初号はまだ倉庫に保管されている。
The first model of this machine is still stored in the warehouse.