wilmott.com

"How American Gold Can Shore Up the Dollar A special Treasury bond backed by the precious metal would strike a blow for sound money."
""Fearing currency erosion, many investors are making “debasement trades” by shifting from dollars to hard assets. The Trump administration could counteract this dangerous trend by introducing a U.S. Treasury security offering gold convertibility at maturity."

https://www.wsj.com/opinion/how-american-gold-can-shore-up-the-dollar-c60e10f6

The aspect of bonds convertible into gold is interesting. India already had some issues with gold backed bonds. 

Sovereign Gold Bond (SGB)

how should a gold bond be structured? zero coupon? Or even negative tax deductible coupon (for storage cost of the gold underlying the bonds in Fort Knox)

In my view this is unlikely to happen before we see a gold price goes much higher. There is only 1 ounce of gold per person on Earth (above ground ). 

US government used to have over 20 million tonns of gold now they officially have about 8 million tonns. Possibly they have plenty of sea shells and oxen as Greenspan indicated in 2002