NFL Rule
 

A flag was thrown on an onside kick - K touched at 2-3 yards early - is the NFL rule different than NFHS - first touching?

Yes, it is called "illegal touching" at that level. Not sure the application is that much different then college, but the rule is different at the NFL level compared to NF rules. I know that much.

Did they tack on yards?

Peace

Item 1: A player of the kicking team may not touch, catch, or recover the ball before it has reached the receiving team’s restraining line, unless it has first been touched by a receiving team player.

Penalty: For illegal touching of a free kick by the kicking team: Loss of five yards, or the receiving team takes possession of the ball at the spot of the illegal touch.

Tack on
 

They announced 5 yards and then announced that it isn't walked off:confused:

It's five yards from the previous spot and rekick or receiving team takes possession of the ball at the spot of the illegal touching.

Thanks
 

:)