The following is a NFHS Clarification from August 17, 2015 (underline = addition & strike through = deletions). Note the down ends on the B16 yard line and the 1st DB foul is against B. In past years, the DB foul on B would be enforced 1/2 distance to the 8 followed by the DB foul against A leaving the ball on the 23. With the new rule change, both DB fouls offset and the ball remains on the 16.
I do not have my 2016 Case Book with me but I am curious how 5.1.2 D reads.
Pages 38-39, 5.1.2 SITUATION D:
With fourth and 5 on B’s 20, A1 is downed on B’s 16-yard line. During the down, the coach of B is on the field arguing with a game official. Following the down, A1 uses profanity. RULING: Since A did not gain a first down on the fourth-down run by A1, B has a new series. Enforcement of the The penalties for the foul on the coach of B and on A1 offset, puts the ball on B’s 23- the ball remains on B’s 16-yard line and first and 10 for B. The line to gain is established and the equipment is set. following the administration of the last penalty.