This ability to be transferred is part of what is meant by the term Negotiability.
"Studies in Civics"
James T. McCleary
A very important characteristic of Negotiability is that it enables a person to grant to another rights which he may not himself possess.
"Studies in Civics"
James T. McCleary
Thus the indorsement of the words "per contract" on the back of a note written at the time of its execution does not affect its Negotiability.
"Putnam's Handy Law Book for the Layman"
Albert Sidney Bolles