countersignature
n. 副署,連署; 會籤
1. a second confirming signature endorsing a document already signed
Please return the duplicate ( n . ) with you countersignature.
請會籤後退回一份.
We return one copy of the contract with our countersignature for your file.
我們退回一份我們已會籤的合同供你方存檔.