Final answer:
The question refers to a 'blank endorsement' on a check, which is simply the signature of the recipient on the back of the check. This allows the check to be freely negotiated unless turned into a restrictive endorsement by adding instructions.
Step-by-step explanation:
An endorsement on the back of a check consisting only of a signature is a blank endorsement. This type of endorsement creates a negotiable instrument, which means the check can be presented for payment by anyone who possesses it.
To convert a blank endorsement into a more secure form, the holder can add instructions such as "for deposit only" to limit how the check can be used, creating a restrictive endorsement.