postal note; postal order; postal money order
Historical term for a small postal money order, abolished in 1951. Now only encountered in historical contexts or older documents.
See also: 郵便為替
Before the war, you could send small amounts of money using a postal note.
The term '小為替' appears in old documents.
Compound of 小 (small) and 為替 (money order). The term reflects its function as a small-denomination postal money order.