Youth mercy rule
There is no longer a youth mercy rule at any level of play.
Shoulder pads and jerseys/pinnies
NFHS rules require that players wear a jersey and that the jersey "shall completely cover the shoulder pads" (the reason given for this is that the manufacturers assume that the shoulder pads will be covered to keep them in place). However, USL Youth rules and MN Youth rules weaken that somewhat by stating, "The jersey, pinnie, or an under jersey should completely cover the shoulder pads, which will help hold them in place."
Jerseys that cover the shoulder pads can always be worn. Pinnies can be used with a shirt underneath to cover the shoulder pads and keep them in place.
Coaches must certify to the officials prior to the game that they have instructed their players on how to wear their equipment, including how the shoulder pads and jerseys/pinnies work together. Thus, this is not something officials should penalize or correct. If a coach believes another coach is endangering players by violating equipment standards, this is generally an issue the coach should report to the league.