Parents behind the backstop

[WinterWillie]

NFHS
Before the game starts, I informed both coaches that I don't want any parents behind the backstop because I believed that was the NFHS's position. (The backstop in this particular field is only ten feet from the plate.) Third inning, pitch catches outside corner for third out and I hear it from behind the backstop. I look back and see about 30 parents from the visitor's team about ten feet behind the backstop. I inform both coaches that I want EVERYONE removed from behind the backstop before the game will continue. (Visitor's coach pulls a HUHA and says its not his problem because he is the visiting team.) I get the home team coach to make everyone sit in the bleachers and the game continues without incident. Can I get a reference to the NFHS's position on anyone being behind the backstop?