indorsement of claim

例句：

1. 1.The company's indorsement of the product is unquestionable.
   公司的背书对产品无可置疑。
2. 2. He signed a contract with the bank, which was later endorsed by the bank manager.
   他与银行签订了合同，银行经理后来对此进行了背书。
3. 3.The signature on the document serves as an indorsement of its authenticity.
   文档上的签名作为其真实性的背书。