Shower Bench

Can anyone direct me to an IRC code or section that states the shower bench should not hold water or should drain to the shower floor.
Thanks in advance.

I don’t know if it’s code, but it is best practice.

Its part of the directions for better bench. Not sure if that’s what they used.

http://www.innoviscorp.com/sites/innoviscorp.com/files/better-bench_installation-trademark.pdf