Uniform Rules Question

What is the rule regarding the jersey being tucked up into the shoulder pads a la Ezekiel Elliott? I thought that was now against the rules? On Maryland's last touchdown run, it looked like the RB had his jersey tucked up into his pads. What would be the penalty for it?

Refs do not want to throw flags for that.

I belive most would just tell the player to not do that.

ARTICLE 5. a. Design.
1. The jersey must have sleeves that completely cover the shoulder pads.
It must not be altered or designed to tear. The jersey must be full length
and tucked into the pants or made even with the waist line. It
must cover all pads worn at or above the waist. Vests and/or a second
jersey worn concurrently during the game are prohibited.

If it was ever called it would be an unsportsmanlike foul and penalized after the result of the play.