Signature签名、署名

Definition: A person's name written in a distinctive way as a form of identification in authorizing a cheque or document or concluding a letter [Oxford Dictionary]

Example:

Six years later, his name appeared as the second of 25 signatures on a document requesting the incorporation of Richmond.

While most signatures were written in longhand, some names were neatly handprinted on blocks.

扩展：A distinctive pattern, product, or characteristic by which someone or something can be identified. [Oxford Dictionary]明显特征、鲜明特色、识别标志

Example:

My signature dish at the time was a thin slice of farmed salmon, seared until crisp on one side and served atop a mound of avocado salsa, surrounded by a herb butter sauce.（招牌菜、特色菜）

It began developing its signature brand of dairy products in 1984.（标志性品牌）

Autograph（名人的）亲笔签名

Definition: A signature, especially that of a celebrity written as a memento for an admirer. [Oxford Dictionary]

Example:

I still have their autographs, written in English and Chinese, in my autograph album.（亲笔签名簿）

Endorsement 背书、票据签字

Definition: The action of endorsing someone or something. [Oxford Dictionary]

Example:

Cheques requiring endorsement

Endorsement of bill of lading be required when take a delivery.

扩展：代言、支持

Example:

His commercial endorsements for everything from running shoes to breakfast cereals will take his earnings to more than ten million dollars a year.（商业代言）