Wikipedia
A gold certificate in general is a certificate of ownership that gold owners hold instead of storing the actual gold. It has both a historic meaning as a U.S. paper currency (1863–1933) and a current meaning as a way to invest in gold.
Banks may issue gold certificates for gold that is allocated (non-fungible) or unallocated ( fungible or pooled). Unallocated gold certificates are a form of fractional-reserve banking and do not guarantee an equal exchange for metal in the event of a run on the issuing bank's gold on deposit. Allocated gold certificates should be correlated with specific numbered bars, although it is difficult to determine whether a bank is improperly allocating a single bar to more than one party.
Usage examples of "gold certificate".
As part of the transition, remaining gold coins and gold certificate paper currency would be called.