The words "valuable security" denote a document which is, or purports to be, a document whereby any legal right is created, extended, transferred, restricted, extinguished or
released, or whereby any person acknowledges that he lies under legal liability, or has not a certain legal right"
Illustration
A writes his name on the back of a bill of exchange" As the effect of this
endorsement is to transfer the right to the bill to any person who may become
the unlawful holder of it, the endorsement is a "valuable security"