noun
personal seal; informal seal
A personal, unregistered seal used for everyday purposes like receiving parcels or internal documents, as opposed to a formally registered 実印 (jitsuin).
宅配便を受け取るときは認印で十分です。
A personal seal is sufficient when receiving a parcel delivery.
会社で使う認印を文房具屋で買った。
I bought an informal seal for office use at a stationery shop.