signing a blank document


Hi everybody,

I am looking for a word or a phrase to describe this action.

"The action when an authorized person sign in a certificate/contract or just a blank paper without its contents or information. For example a certificate without the order of certificate..."

Many thanks for your attention!
  • Tiento

    Many thanks to your responses :)

    May be my explanation made you confused. Because I explained the word I am looking for based on the meaning of my own language. Actually, signing in a blank check is one kind of that action. It also includes the action when an authorized person sign in a certificate, such as a diploma certificate but did not show the name of the certified person. The reason they do that is when someone get that certificate, they can become the owner of it.

    thank you very much everyone!