special revenue
A government finance term referring to non-ordinary revenue, such as proceeds from asset sales or one-off taxes, as opposed to regular tax revenue.
Special revenue is recorded separately from ordinary tax revenue.
一般歳入 refers to general or ordinary revenue, typically from regular taxes, while 特別歳入 is special, non-recurring revenue.
Compound of 特別 (special) and 歳入 (annual revenue). The term is a straightforward combination used in public finance contexts.