Definition - What does Blank Endorsement mean?
A blank endorsement is a financial instrument that holds the name of the endorser but not of any specific endorsed person. Commonly referred to as a blank check, as long as a check or other financial instrument has the signature of the endorser on it, then it can be left blank and passed to another person to fill in when they are ready.
Justipedia explains Blank Endorsement
An advantage of a blank endorsement is when the amount the check is written for is undecided at the point where it is being signed, such as in an office administration system.